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Title: Milestones in impact assessment research in the CGIAR, 1970-1999
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Title: Milestones in impact assessment research in the CGIAR, 1970-1999
Physical Description: vi, 37 p. : ; 26 cm.
Language: English
Creator: Pingali, Prabhu L., 1955-
Consultative Group on International Agricultural Research -- Technical Advisory Committee
Publisher: CGIAR
Place of Publication: Mexico
Publication Date: 2001
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Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 14-16).
Statement of Responsibility: Prabhu L. Pingali.
General Note: "With an annotated bibliography of impact assessment studies conducted in the CGIAR, 1970-1999, prepared by Matthew P. Feldman."
General Note: "Standing Panel on Impact Assessment (SPIA), Technical Advisory Committee (TAC) of the Consultative Group on International Agricultural Research (CGIAR)."
Funding: Electronic resources created as part of a prototype UF Institutional Repository and Faculty Papers project by the University of Florida.
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Resource Identifier: oclc - 47217898
lccn - 2001405492
isbn - 9706480765

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Table of Contents
    Front Cover
        Front cover
    Title Page
        Page i
    Copyright
        Page ii
    Dedication
        Page iv
    Foreword
        Page v
        Page vi
    Milestones in impact assessment research in the CGIAR, 1970-1999
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
    Impact assessment studies conducted in the CGIAR, 1970-1999: an annotated bibliography
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
    Back Cover
        Back cover
Full Text

r r 'r r, 1- r- 1

in Impact Assessm
Nei theAIm


ent


Resea rch
Research










Milestones in Impact


Assessment Research in the


CGIAR, 1970-1999


Prabhu L. Pingali*



With an annotated bibliography of impact
assessment studies conducted in the CGIAR, 1970-


1999, prepared by Matthew P. Feldmann'


Standing Panel on Impact Assessment (SPIA),
Technical Advisory Committee (TAC) of the
Consultative Group on International
Agricultural Research (CGIAR)













* Prabhu Pingali is Director of the Economics Program at the International Maize and
Wheat Improvement Center (CIMMYT), Mexico. He presented an earlier version of this
paper at the Impact Assessment Workshop organized by the Standing Panel on Impact
Assessment (SPIA) of the Technical Advisory Committee (TAC) of the Consultative
Group on International Agricultural Research (CGIAR), 3-5 May 2000. When this work
was underway, Matthew P. Feldmann was a CIMMYT Economics Program Research
Assistant. The views expressed in this paper and bibliography do not necessarily
reflect policies of SPIA, TAC, the CGIAR, or CIMMYT.












The Consultative Group on International Agricultural Research (CGIAR) (www.cgiar.org) is
an international association of 58 public and private sector members that supports 16
international Future Harvest centers (www.futureharvest.org) that conduct research with
farmers, scientists, and policymakers to alleviate poverty and increase food security while
protecting natural resources. The Standing Panel on Impact Assessment (SPIA) of the
CGIAR Technical Advisory Committee (TAC) provides information on the impact of past
CGIAR outputs with respect to CGIAR goals, complements the ex post assessment activities
of the Future Harvest centers, and provides feedback to strategic planning and priority
setting in the CGIAR. CIMMYT (www.cimmyt.org), a Future Harvest Center, is a non-
profit, scientific research and training organization that works with agricultural research
institutions worldwide to improve the profitability, productivity, and sustainability of
maize- and wheat-based cropping systems for poor farmers.
The opinions expressed in this publication are the sole responsibility of the authors. The
designations employed in the presentation of materials in this publication do not imply the
expression of any opinion whatsoever on the part of the CGIAR, SPIA, CIMMYT, or
contributory organizations concerning the legal status of any country territory, city, or area,
or of its authorities, or concerning the delimitation of its frontiers or boundaries. Fair use of
this material is encouraged by the publishers. Proper citation is requested.
Correct citation: Pingali, P.L. 2001. Milestones in Impact Assessment Research in the CGIAR,
1970-1999. With an Annotated .,I.... '/.il. of Impact Assessment Studies Conducted in the
CGIAR, 1970-1999, Prepared by Matthew P. Feldmann. Mexico, D.E: Standing Panel on Impact
Assessment, Technical Advisory Committee of the Consultative Group on International
Agricultural Research.
Abstract: This report identifies "milestones" in impact assessment research by the
international research centers of the Consultative Group on International Agricultural
Research (CGIAR). Milestones are theoretical or methodological research contributions that
identify and analyze new areas of impact assessment research and that have been published
in refereed publications. The report covers the development of impact assessment research
in the CGIAR, charting the progression from assessments of the impact of germplasm
adoption and crop management research in the 1970s and 1980s, to formal rate of return and
benefit distribution studies in the 1980s, research on spillover and intersectoral impacts in
the 1980s and 1990s, and gender and environmental impact assessment research as the 1990s
progressed. The role of the CGIAR scientists in this evolution and broadening of scope is
documented, as well as the CGIAR's contribution to (and benefits from) impact assessment
research in universities and non-CGIAR research centers The report also highlights the role
of impact assessment research in producing a picture of solid accomplishments of CGIAR
research with respect to poverty, food security, and the environment. The report concludes
with comments on future needs for impact assessment research within the CGIAR. An
annotated bibliography of CGIAR impact assessment studies follows the report and serves
as a useful guide to this significant area of CGIAR research.


ISBN: 970-648-076-5
AGROVOC descriptors: CGIAR; Agricultural development; Economic development;
Research institutions; Research projects; Diffusion of research; Technology transfer;
Innovation adoption; Environmental impact assessment; International cooperation
AGRIS category codes: E14 Development Economics and Policies
A50 Agricultural Research
Dewey decimal classification: 338.16


Printed in Mexico by the International Maize and Wheat Improvement Center (CIMMYT)
for the Consultative Group on International Agricultural Research (CGIAR).










Dedication



This paper is dedicated to Vernon Ruttan, who was the first
economist to work for a CGIAR Center (the International Rice
Research Institute, 1963-1965). Economists-past and present-in
the CGIAR owe him our gratitude for leading the way.






Acknowledgments



Hans Gregersen, the Chairman of the Standing Panel on Impact
Assessment (SPIA) of the Technical Advisory Committee (TAC), and
Guido Gryseels, the Deputy Executive Secretary of TAC, were
instrumental in helping me conceptualize and write this paper. They
provided substantive comments on drafts of the paper and provided
financial support for its publication. The first draft of this paper was
written during a one-week personal retreat at Stanford University in
March, 2000. My long discussions with Wally Falcon at that time, and
his subsequent comments on various versions of the paper, helped
me enormously. Comments, suggestions, and help from Alex
McCalla, Robert Herdt, Timothy Reeves, Michael Morris, and several
members of the CIMMYT Economics Program are gratefully
acknowledged. Comments and criticisms from the participants of the
SPIA workshop on impact assessment, held in May 2000 in Rome,
helped clarify my thinking and provided useful leads to references
that I had previously overlooked. I am also grateful to CIMMYT
colleagues Kelly Cassaday, Head of Information Services; Satwant
Kaur, CIMMYT Economics Program Editor; and Miguell Mellado,
Head of Production, for editing and publishing this review.











Foreword


It is quite widely accepted that the CGIAR
has had, over its lifetime, a significant,
sustainable impact on poor people by
helping to develop the technologies and
agricultural management tools that have
permitted increased food security and
dramatic lowering of the cost of producing
the major food crops of the world. This, in
turn, has benefited both poor producers and
consumers. A recent SPIA study has
documented and confirmed this conclusion
at the CGIAR-wide level (Evenson and
Gollin 2001).
What is not so well known is the significant
contributions that CGIAR scientists have
made in advancing the theory and methods
of impact assessment which have been used
to identify and estimate the people-related
impacts of agricultural research. For the
first time, this "other" role of the CGIAR
has been systematically documented
through the accompanying study of
"milestones" in CGIAR impact assessment
research. The author, Dr. Prabhu Pingali,
Director of the Economics Program at
CIMMYT, has been intimately involved in
this work over the past decades and is an
appropriate person to document CGIAR
contributions. This paper was originally
prepared for a May 2000 workshop
sponsored by SPIA, "The Future of Impact
Assessment in the CGIAR: Needs,
Constraints, and Options" (TAC / SPIA,
forthcoming).
Dr. Pingali carries out the study in an
objective fashion by identifying
"milestones" in impact assessment research
conducted within the CGIAR centers.
Milestones are defined as research
contributions that identify and analyze new
areas of impact assessment research,
whether they be theoretical or


methodological. A key characteristic of
milestones is that they are quickly followed
by other, similar studies within and outside
the CGIAR that verify the findings of the
milestone research. In all cases, the
milestone research is published in refereed
publications. Given these defining
characteristics of "milestone" research, it is
possible to develop an objective picture of
the importance of CGIAR contributions in
the evolving world of impact assessment
research.
The study traces the evolution of this
research in the CGIAR, concluding that
there is a logical evolution from the
relatively narrow focus in the 1970s and
1980s on assessment of impacts of
germplasm adoption and crop management
research, to formal rate of return and benefit
distribution studies starting in the 1980s.
The next major broadening in the 1980s was
to work on spillover and intersectoral
impacts. Finally, in the 1990s the activity has
broadened further into gender and
environmental impact assessment research.
The role of the CGIAR scientists in this
evolution and broadening of scope has been
important. In addition to contributions
made by CGIAR scientists while working
with the CGIAR, it should be noted that
many of these researchers have moved on
to become leaders in impact assessment
research in universities and research centers
where they still build on and benefit from
their early impact assessment research in
the CGIAR. Thus the indirect contributions
of the CGIAR are widespread. At the same
time, as Dr. Pingali emphasizes, the CGIAR
has benefited greatly from the work of
others and the interactions that have been











possible with scientists in both developing
and developed countries.
In tracing the milestones in CGIAR impact
assessment research, Dr. Pingali paints a
broad yet in-depth picture of how activities
within the CGIAR System have contributed
to this growing and dynamic field. At the
same time, as he points out, the milestone
research and use of its methodological
results in more routine impact assessments
of CGIAR research have produced a picture
of solid accomplishments and impacts of
CGIAR research with respect to the main
goals of the System, which are to have


agricultural research results applied in
such a way that there are sustainable
impacts on poverty, food insecurity, and
the environmental resources on which all
agricultural production depends. He
provides some insights into the road
ahead and the gaps that remain to be
filled by future generations of CGIAR
impact assessment researchers.
SPIA commends Dr. Pingali for this study,
one that itself will be a milestone in
synthesis of past activity in the CGIAR in
the area of impact assessment research.


Hans Gregersen
Chair, Standing Panel on Impact
Assessment
Technical Advisory Committee
CGIAR











Milestones in Impact Assessment

Research in the CGIAR, 1970-1999

Prabhu L. Pingali


Introduction

The Consultative Group on International
Agricultural Research (CGIAR) probably
has had greater impact on agricultural
production, productivity, and the
livelihoods of the rural poor in the world
than any other agricultural research
organization. This paper does not intend to
document the substantial impacts of the
CGIAR but rather to dwell on the stock and
state of impact assessment research
conducted by CGIAR scientists, especially
economists. What is not so widely realized
is that over the past three decades
contributions by CGIAR economists and
other scientists to the science of impact
assessment have in many cases been
groundbreaking, and they have created
milestones in the ever-increasing body of
technical literature on impact assessment
theory and methods. In numerous instances,
the CGIAR was the forerunner of a
substantial body of academic research on
particular themes related to impact
assessment.
For the purposes of this paper, a milestone
is defined as a research contribution that
identified a new area or theme of impact
assessment research. It can also include
methodological contributions. In all cases,
the seminal contributions (milestones) were
quickly followed by other studies, both
from within and outside the CGIAR, which
verified the findings or applied the
methodology developed in the study. In all
cases, the milestone contributions were
published in refereed journal articles, books,
or official, peer-reviewed publications of a


CGIAR Center (not working papers and other
non-refereed documents).
Before proceeding with this review, it is
important to be explicit about its unique
features and shortcomings. This review
documents and highlights the important
milestones in impact assessment research that
can be attributed to current and past CGIAR
economists and social scientists. It covers
only research on the impacts of technology
and management practices; it does not cover
the contributions of CGIAR scientists to
impact assessment research related to policy
research and policy advice. Owing to the
limitations of my own knowledge, the focus
has been mainly on milestones related to crop
research in the CGIAR. Activities related to
such themes as livestock, trees, and capacity
strengthening have not received adequate
attention. At the same time, it should be
pointed out that impact assessment research
related to these themes is also much less, and
there are few CGIAR milestones in these
areas that can be discussed. The need for
substantial gap filling, in areas covered and
studies cited, is recognized and all
suggestions will be appreciated.


Categories of Impact
Assessment Research

For the purposes of this paper, CGIAR impact
assessment research is divided into six
categories:
1. Adoption and farm-level production/
productivity/ profitability impact of
modern varieties;











2. Adoption and impact of technical
change in crop management and
improved input-use efficiencies;
3. Distribution, equity, and food security
impacts, including poverty alleviation;
4. Environmental, ecological, and human
health impacts;
5. Intersectoral linkages: agriculture as an
engine of growth; and
6. Impacts on the research system
through spillover benefits, training,
and networks.
Most of the early (1970s and 1980s) impact
assessment work in the CGIAR was
concentrated in the first two categories.
Interest in-and significant contributions
to-the remaining categories of research
came about only in the late 1980s and
1990s (Figure 1). The broadening agenda
of impact research in the CGIAR,
especially in the 1990s, reflects to a large
extent the broadening research agenda of
the CGIAR itself and also the changing
public perceptions about the impacts of
agricultural modernization and
technological change. The impacts
research agenda of the 1990s also reflects a
desire among CGIAR economists to take
on more challenging and difficult-to-
measure impacts, such as the
environmental and ecological impacts of
agricultural intensification and
modernization.


Adoption and Farm-level
Production/Productivity/
Profitability Impact of
Modern Varieties

The extent of adoption of modern varieties
(MVs) is now well established, at least for the
major cereal crops. CGIAR contributions to
the content of varieties released by national


Germplasm adoption
1970 1980 1990 2000 >

Figure 1. The expanding agenda of impact
assessment research.


agricultural research systems (NARSs) are well
known on a global basis for rice, wheat, and
maize and on at least a regional basis for other
CGIAR mandate crops.
Since the early 1970s, substantial work has
been done on the extent of adoption and
farm-level impact of modern, high-yielding
varieties of rice, wheat, and maize. Similar
work for other crops, such as cassava,
sorghum, millets, and potatoes, followed in
the 1980s and beyond. The pioneering
studies in assessing the global extent of MV
adoption and CGIAR impact were
conducted on rice and wheat by Dalrymple
in the early to mid-1970s (Dalrymple 1977,
1978, 1986). Dalrymple (1978) provided a
quantitative verification of the common
perception that the Green Revolution was
underway for rice and wheat (Figure 2): "By
1976 /77 approximately 30 million hectares
of wheat and 25 million hectares of rice in
the developing world was planted to high
yielding varieties."
Dalrymple's work triggered several in-
depth adoption studies, particularly by the
International Rice Research Institute (IRRI)
and International Maize and Wheat











Area on which MVs adopted
(million ha)
30


Source: Dalrymple (1978).

Figure 2. Green Revolution in Asia: The
first decade.



Improvement Center (CIMMYT). Herdt and
Capule (1983) and Byerlee and Moya (1993)
provided detailed assessments of MV
adoption for rice and wheat, respectively, in
which global, regional, and national
adoption figures were differentiated by type
of production environment (favorable and
unfavorable). Byerlee's work in particular
concentrated on identifying the CIMMYT
content of wheat varieties released around
the world. Other adoption and impact
studies that traced CGIAR content in crop
releases included Walker and Ryan (1991)
for sorghum and millet, Evenson and David
(1993) for rice, L6pez-Pereira and Morris
(1994) for maize, and Walker and Crissman
(1996) for potatoes. The recent effort by SPIA
to evaluate the impacts of crop
improvement research builds on a long
history of CGIAR efforts and expertise in
this area (see Evenson and Gollin 2001, who
provide detailed adoption and impact
information on all CGIAR crops).
The CGIAR Centers have generated substantial
empirical evidence on the biophysical and
socioeconomic factors that influence the
profitability of adopting improved germplasm.
IRRI's "consequences of modern rice


technologies" studies of the mid-1970s (see
IRRI 1978) and CIMMYT's "studies in the
adoption of new agricultural technology"
(see Winklemann 1976) were the absolute
forerunners in adoption case studies. These
early efforts identified the impact on farm-
level production and income of switching
from traditional to modern varieties. The
IRRI and CIMMYT studies were done in a
standardized case study format across
several countries. At CIMMYT, for example,
case studies initially started in Mexico and
quickly expanded across Asia, Africa, and
Latin America. By the early 1980s, about
two dozen detailed case studies from
around the developing world had
documented the farm-level consequences of
adopting modern rice, wheat, and maize
germplasm. In addition to documenting the
positive production and income benefits of
MVs, these early adoption studies helped
allay fears that the Green Revolution had a
bias toward large-scale farmers and an
adverse effect on poor farmers and landless
laborers.
Aside from documenting the consequences of
adopting MVs, CGIAR researchers have made
substantial contributions to the literature on the
factors constraining the adoption of modern
technologies. In his study of rice technology,
Herdt (1979) documented the biophysical
and socioeconomic factors that explained
the "yield gap" in farmers' fields (the yield
gap is the difference between the yield that
is economically achievable and the yield
that is actually obtained). A follow-up
publication by Herdt and Mandac (1981)
identified the technical and economic
constraints to exploiting yields and profits
from the adoption of MVs. Herdt's work on
constraints to adoption and technology use
inspired a whole literature on technical and
economic efficiency. CIMMYT's adoption
case studies for Latin America, Asia, and
Africa also provided detailed information
on constraints. Village-level studies (VLS)
by the International Crops Research
Institute for the Semi-Arid Tropics
(ICRISAT) provided similar information for











the semi-arid tropics of India and, later, for
West Africa. The VLS dataset that entered
the public domain in the mid-1980s
spurred a series of doctoral theses (112 at
last count), mainly from universities in the
United States, whose authors attempted
empirical assessments of a large gamut of
farmer behavior in the context of technical
change.
Other important contributions emerging
from case studies of adoption and
constraints were detailed assessments of
risk attitudes, studies of the variability of
farm production, and credit studies.
Binswanger's study of risk, done at
ICRISAT, was a seminal contribution to the
understanding of farmers' attitudes to risk
and how those attitudes constrain
technology adoption (Binswanger 1980a).
Binswanger's work also made significant
contributions to the theoretical literature
on risk. Anderson and Hazell's (1989)
volume on variability in grain yields
provided an important synthesis of
evidence on production variability in
agricultural systems that had recently
switched to MVs. The volume covered
most CGIAR crops and all continents
where the CGIAR Centers worked. The
contention that MVs may be more risky and
therefore less attractive to farmers does not
seem to have held up in practice. Stochastic
dominance tests of the distribution of
returns from improved and traditional
varieties typically show new varieties to be
dominant. The following studies provided
crop-specific results for sorghum and
millets (Walker 1989; Witcombe 1989) and
rice (Flinn and Garrity 1989; Coffman and
Hargrove 1989). More recent studies at
CIMMYT (CIMMYT 1991) for wheat and at
ICRISAT for millet (Adesina 1988; Shapiro
1990) have reported reduced coefficients of
variation for fields over time (Table 1).


Studies estimating the rates of return to CGIAR
commodity research investments have consistently
shown the investment to be extremely profitable.
The returns to investments in high-yielding
modern germplasm have been measured in
great detail by several CGIAR Centers over
the last few decades. These studies found
high returns to the CGIAR strategy of
germplasm improvement. The very first
studies that calculated the returns to research
investment were conducted at IRRI for rice
research investments in the Philippines
(Flores-Moya et al. 1978) and at the
International Center for Tropical Agriculture
(CIAT) in Colombia (Scobie and Posada 1977,
1978). More detailed evidence on the high
rates of return to public-sector investments in
agricultural research was provided by the
International Service for National
Agricultural Research (ISNAR) (Echeverria
1990) and the International Food Policy
Research Institute (IFPRI) (Pardey et al. 1992).
Table 2 presents a synthesis of early rate of
return studies. We ought to recognize,
however, that these high rates of return are
partly biased by the fact that in general only
success stories are incorporated in rate of
return studies. For a detailed synthesis of the
numerous studies conducted across crops and
countries, see Evenson (2001) and Alston et al.
(2000). Alston et al. concluded from a review
of 289 studies that there was no evidence to
support the view that the rate of return to
agricultural research and development has
declined over time.


Table 1. Expected income and risk of traditional
and improved millet technologies in Niger

Author Location Traditional Improved

Adesina (1988) Maradi 156 195
(52) (42)
Shapiro (1990) Libure 446 628
(52) (56)
Kouka 301 409
(49) (39)

Note: Income figures are in US$ (CFA 298/US$ 1). The
number in parentheses is the coefficient of variation of
income (%).












Table 2. Returns to CGIAR research: first-generation studies

Results
Country (rate of
Study Year (region or institute) Commodity Period return) a


Evenson and Flores 1978 Asia
Asia (national)
Asia (international)
Flores et al. 1978 Philippines
Scobie and Posada 1978 Colombia
Martinez and Sain 1983 Panama (IDIAP-Caisan)
Nagy 1983 Pakistan
Pakistan
Ambrosi and Cruz 1984 Brazil (EMBRAPA-CNPT)
Monares 1984 Rwanda
Salmon 1984 Indonesia
Muchnik 1985 Latin America
Unnevehr 1986 Southeast Asia
Librero and Perez 1987 Philippines
Norton et al. 1987 Peru (INIPA)
Peru (INIPA)
Peru (INIPA)
Peru (INIPA)
Peru (INIPA)
Peru (INIPA)
Echeverria et al. 1989 Uruguay
Evenson 1988 Paraguay
Norgaard 1988 Africa



Evenson and da Cruz 1989 South America (PROCISUR)
South America (PROCISUR)
South America (PROCISUR)
Schwartz et al. 1989 Senegal (CRSP)


Rice
Rice
Rice
Rice
Rice
Maize (on-farm research)
Maize
Wheat
Wheat
Potato seed
Rice
Rice
Rice quality
Maize
Aggregate
Rice
Maize
Wheat
Potatoes
Beans
Rice
Crops
Cassava
(biological control)


Wheat
Soybeans
Maize
Cowpeas


1950-65
1966-75
1966-75
1966-75
1957-64
1979-82
1967-81
1967-81
1974-90
1978-85
1965-77
1968-90
1983-84
1956-83
1981-2000
1981-2000
1981-2000
1981-2000
1981-2000
1981-2000
1965-85
1988
1977-2003



1979-88
1979-88
1979-88
1981-87


32-39%
73-78%
74-102%
46-71%
79-96%
188-332%
19%
58%
59-74%
40%
133%
17-44%
61%
27-48%
17-38%
17-44%
10-31%
18-36%
22-42%
14-24%
52%
75-90%
Benefit-
cost ratio
of 149:1
110%
179%
191%
63%


Source: Echeverria (1990).
a Depending on the study, these are average or marginal rates of return. More than one value means a range of
returns depending upon different assumptions or different periods of analysis. Results are rounded. Results of
conducting sensitivity tests on various parameters of the models are not presented in this table.











Adoption and Impact of
Technical Change in Crop
Management and Improved
Input-use Efficiencies

Savings in production costs have come about
from technical change in crop management and
increased input-use efficiencies. Once MVs
have been adopted, the next set of
technologies to make a significant
difference in reducing production costs
includes machinery, land management
practices (often in association with
herbicide use), fertilizer use, integrated pest
management, and (most recently) improved
water management practices. Although
many Green Revolution technologies were
developed and extended in package form
(e.g., new plant varieties plus
recommended fertilizer, pesticide, and
herbicide rates, along with water control
measures), many components of these
technologies were taken up in a piecemeal,
often stepwise manner (Byerlee and Hesse
de Polanco 1986). The sequence of adoption
is determined by factor scarcities and the
potential cost savings achieved. Herdt
(1987) provided a detailed assessment of the
sequential adoption of crop management
technologies for rice in the Philippines.
Traxler and Byerlee (1992) provided similar
evidence on the sequential adoption of crop
management technologies for wheat in
Sonora, northwestern Mexico.


Machinery Adoption and Use
The early adoption of tractors in the high-
potential agricultural areas where the Green
Revolution first occurred, particularly in
Asia, prompted a series of in-depth studies
of the impacts of farm mechanization.
Binswanger's study for ICRISAT on the use
of tractors in South Asia was a pioneering
effort in this area (Binswanger 1978). In the
early to mid-1980s, IRRI conducted detailed
farm-level studies across several Asian


countries on the impact of small-farm
mechanization (IRRI 1986). More recent
studies at IRRI on the consequences of
mechanization have concentrated on
harvest and post-harvest operations,
including small mills used predominantly
by female household members. An
important contribution of the
mechanization studies was the finding that
farm machinery is also adopted
sequentially. Machinery is first adopted for
power-intensive operations such as tillage
and transport, even in labor-abundant
societies. Control-intensive operations such
as weeding and harvesting, which require
knowledge and judgment, are mechanized
only as wages rise (Herdt 1983; Binswanger
1984). Consequently, most studies on the
impacts of tractor use (for land preparation)
found minimal labor displacement even in
labor-abundant societies (see Pingali et. al.
1987 for a detailed review of the farm
mechanization literature).


Fertilizer Use
Given the importance of fertilizer for
realizing the yield potential of MVs, the
CGIAR has given surprisingly little
attention to assessing the adoption and
impact of fertilizer. David's (1976) study of
factors that determine fertilizer use at the
farm level and David and Barker's (1978)
assessment of fertilizer responsiveness are
still the best pieces of work in this area.
David and Otsuka (1994) provide more
recent information on the determinants of
farm-level fertilizer use for rice. Despite the
history of high fertilizer subsidies in
developing countries, relatively little
research has been done on the economic
incentives and technological options for
increasing fertilizer-use efficiency. Few ex
post impact studies have examined
alternatives to chemical fertilizer, including
organic fertilizers (e.g., Azolla, Sesbania),
crop rotations, and improved fallows. The
limited CGIAR effort to develop and
promote these technologies and their











limited adoption probably explain the small
number of adoption and impact studies
conducted on non-chemical fertilizers by the
centers. There are two significant exceptions:
the work of McIntire et al. (1992) at the
International Livestock Center for Africa
(ILCA)1 on crop-livestock integration and of
Franzel et al. (1999) at the International
Centre for Research in Agroforestry (ICRAF)
on improved fallows. McIntire et al.
conducted an Africa-wide survey on the
extent of crop-livestock integration and its
impact on soil fertility management. Franzel
et al. have been documenting the extent of
adoption of improved fallow systems across
East Africa and the consequences for
sustaining soil fertility in smallholder
production systems.


Integrated Pest Management
Compared to fertilizer use, integrated pest
management (IPM) has received far greater
attention from the CGIAR's commodity
research centers. See Waibel (2000) for a
detailed review and assessment of IPM
research across the CGIAR Centers. One of
the earliest studies on insecticide use was a
study on rice (Herdt et al. 1984) conducted
as part of a yield constraints study in several
countries of Asia between 1973 and 1979.
Herdt et al. concluded that the expected
returns to rice production are lower for
farmers who apply insecticides on a
prophylactic basis than for farmers who
apply no insecticides at all. This result was
validated in on-farm trials by Litsinger
(1989) and Waibel (1986).
Three very important studies related to IPM
have been conducted in recent years: a study
by the International Institute of Tropical
Agriculture (IITA) on biological control of
cassava mealybug in Africa; an IRRI study of
IPM in Asian rice production; and a study
by the International Potato Center (CIP) on


IPM practices in Andean potato
production. IITA's work on cassava
mealybug control (Norgaard 1988) was the
very first study that attempted to estimate
the ex post returns to a biological control
program. The benefit-cost ratio turned out
to be 149:1, triggering an enormous interest
in the cassava mealybug program (then
under evaluation) and in biological control
programs in general. Although Waibel
(2000) has cautioned that the returns to
crisis research, such as the cassava
mealybug program, are generally higher
than returns to non-crisis research, such as
germplasm improvement, it would be safe
to conclude that investments made in
mealybug control were extremely
worthwhile. IRRI's research on the impact
of IPM documented the declining levels of
insecticide used on rice and validated
earlier findings through farm survey data
that natural control (a zero-pesticide
strategy) was the most profitable option for
farmers, especially when health costs were
taken into account (Rola and Pingali 1993;
Pingali et al. 1994; Pingali and Roger 1995).
The CIP study followed a design similar to
that of the IRRI study, but it found a
positive productivity benefit to insecticide
use and hence a more crucial production
versus health trade-off for insecticide
applications in Andean potatoes (Crissman
et al. 1998).
Although host-plant resistance has always
been the cornerstone of any IPM strategy,
little work has been done to assess the
impact of host-plant resistance on
controlling pest losses and reducing yield
variability. The exception is the recent work
on returns to breeding for rust resistance in
wheat at CIMMYT (Smale et al. 1998).
Smale et al. not only determined the
economic returns to breeding for durable
rust resistance but provided a methodology
for evaluating the returns to investments in


1 Now the International Livestock Research Institute (ILRI).











such "maintenance breeding" activities.2
Maintenance breeding is crucial to the long-
term relevance and viability of any breeding
program, yet it remains quite invisible in
donor portfolios and CGIAR priority
setting.


Distribution, Equity, and

Food Security Impacts

Widespread adoption of modern seed-fertilizer
'. 1 1,-I, led to a significant shift in the food
supply function, contributing to a fall in real
food prices. Some of the very early work on
the impact of the Green Revolution was
directed towards understanding its effects
on market prices and food security. The
primary effect of agricultural research on
the non-farm poor, as well as on the rural
poor who are net purchasers of food, is
through lower food prices:
The effect of agricultural research on
improving the purchasing power of the
poor-both by raising their incomes and
by lowering the prices of staple food
products-is probably the major source
of nutritional gains associated with
agricultural research. Only the poor go
hungry. Because a relatively high
proportion of any income gains made by
the poor is spent on food, the income
effects of research-induced supply shifts
can have major nutritional implications,
particularly if those shifts result from
technologies aimed at the poorest
producers.
Alston et al. (1995:85)
Early efforts to document the impact of
technological change and the consequent
increase in food supplies on food prices and
income distribution were made by Hayami
and Herdt (1977) at IRRI, Pinstrup-


Andersen (1976) and Scobie and Posada
(1978) at CIAT, and Binswanger (1980b) at
ICRISAT. Pinstrup-Andersen argued
strongly that the primary nutritional
impact for the poor came through the
increased food supplies generated through
technological change.
The profitability of modern farming systems
has been maintained despite falling food prices
(in real terms), owing to a steady decline in the
cost per ton of production. The point that
producers have continued to benefit from
technological change despite falling output
prices has not been emphasized
adequately in the literature on research
impacts, although empirical evidence does
show quite clearly that the cost per ton of
production has fallen significantly. Most of
the empirical data on changes in unit
production costs is on rice. The very first
study comparing unit production costs of
modern and traditional varieties was done
by IRRI (1972) for several Asian locations
and found significantly lower costs per ton
of production of modern compared to
traditional varieties. More recent studies
have documented trends in the cost per
ton of rice production over time (see
Pingali et al. 1997:43 for several Asian
locations and Hossain 1998:331 for
Bangladesh). Consistently across several
Asian countries, unit production costs
have tended to decline over time, and over
the same period, production costs have
generally tended to be lower than output
prices. Empirical evidence for the long-
term decline in unit costs of production
also exists for wheat; see Sidhu and
Byerlee (1992) for evidence from the
Indian Punjab and numerous publications
for evidence from the Yaqui Valley of
northwestern Mexico, the starting point for
the Green Revolution in wheat.


2 In crop improvement research, "maintenance breeding" can be defined as any breeding activity that
seeks to preserve yield potential and yield stability by maintaining a crop's genetic resistance to
evolving biotic stresses such as diseases and pests.











The impact and benefits of technological change
have varied by ecological domain, socioeconomic
factor, and gender. Many studies have
addressed the differential impact of
technological change in favorable and
unfavorable production environments.
David and Otsuka (1994) conducted a study
on the differential impact of technological
change across rice environments in Asia.
They found that although the favorable,
high-potential environments gained the
most in terms of productivity growth, the
less favorable environments benefited as
well through technology spillovers and
through labor migration to more productive
environments. According to David and
Otsuka, wage equalization across favorable
and unfavorable environments was one of
the primary means of redistributing the
gains of technological change. Renkow
(1993) found similar results for wheat
grown in high- and low-potential
environments in Pakistan. Byerlee and
Moya (1993), in their global assessment of
the adoption of wheat MVs, found that over
time the adoption of MVs in unfavorable
environments caught up to levels of
adoption in more favorable environments,
particularly when germplasm developed
for high-potential environments was further
adapted to the more marginal
environments.
Income distribution effects across the
various socioeconomic groups within a
rural community have received some
attention in the CGIAR impact literature. In
a detailed study of North Arcot District of
Tamil Nadu, India, Hazell and Ramaswamy
(1991) estimated the distribution of benefits
of technological change across landless
laborers, tenant farmers, and small and
large landowners. David and Otsuka's
(1994) study paid particular attention to
effects on landless labor and tenant farmers.
Their results validated the findings of
IRRI's (1978) consequences study, which
found that the benefits were shared across
the various groups. The early criticism that


the Green Revolution had benefited only
large-scale farmers was negated by the
findings of all of these studies.
In recent years, the differential impact
literature has focused on identifying the
distribution of benefits between men and
women farmers and male- and female-
headed households. Paris from IRRI, and
Quisumbing et al. from IFPRI, have
conducted several studies on the subject.
The general finding across crops and
continents is that women farmers and
female-headed households have gained
proportionally less than their male
counterparts. Paris (1998) has contended
that it is not gender alone that determines
whether an individual benefits from
technological change, however, but rather
the initial social and economic status of the
individual. Women from land-owning
households who have some control over the
land benefited substantially from
technological change relative to women
from poor, landless households.
Quisumbing et al. (1995) concluded from a
ten-country study that among the very poor
the economic welfare of male- and female-
headed households differed very little.
Differences emerged only where cultural or
institutional factors prevented equal
participation in the labor force, as in
Bangladesh. For excellent recent reviews of
the literature, see Doss (1999) on African
maize farming systems and Paris (1998) on
rice in Asia.


Environmental, Ecological,

and Human Health Impacts

The environmental, ecological, and human
health impacts of modern '.. mI, ,1i, have
received limited attention from the CGIAR
Centers. There are a few significant
exceptions to this generalization, including
the research on genetic diversity conducted
by CIMMYT, on pesticides and health by
IRRI and CIP, and on soil erosion in the











hillsides of Central America by IFPRI, CIAT,
and CIMMYT. A good deal of
environmental impact assessment is being
done at the CGIAR Centers now, but results
have not been published and therefore are
not included in this review. The works cited
above were all groundbreaking, in terms of
the problems they tackled as well as their
methodological contributions.
From the very early days of the Green
Revolution, the CGIAR has been accused of
reducing crop genetic diversity in
subsistence farming systems through the
widespread promotion of MVs. Smale was
one of the first economists in the CGIAR to
investigate how intensification and use of
MVs affected genetic diversity; she assessed
the current stock of diversity in farmers'
fields as well as farmers' incentives for
conserving diversity (see Smale 1998 for
case studies of wheat, maize, and rice). A
substantial joint research effort by
CIMMYT, IFPRI, and the International Plant
Genetic Resources Institute (IPGRI)
continues to document changes in genetic
diversity in intensive wheat production
systems in China, India, and Pakistan.
The impact of intensive and injudicious
pesticide use was another issue that dogged
the commodity centers of the CGIAR for
several decades. While the CGIAR
responded by promoting IPM and safer
pesticide use, studies that directly
addressed the impacts of pesticides were
not conducted until the late 1980s. IRRI's
study of the impact of pesticides in rice
production on human health was a
pioneering effort that created renewed
interest in IPM research (Rola and Pingali
1993; Antle and Pingali 1994; Pingali et al.
1994; Pingali and Roger 1995). The CIP
study on pesticides in potato production
was done soon afterward (Crissman et al.
1998). Both the IRRI and CIP studies,
conducted in areas of intensive pesticide
use, found that adverse health effects could
be attributed directly to pesticide use. The
similarity in health findings among rice


farmers in the Philippines and potato
farmers in Ecuador was striking, but as
noted previously, the IRRI study found that
returns to pesticide use were negative when
health effects were explicitly accounted for,
whereas the CIP study found continued
positive returns even when health costs
were considered.


Inter-sectoral Linkages:
Agriculture as an Engine of
Growth

Studies by CGIAR economists have provided
empirical support to the proposition that growth
in the agricultural sector has economy-wide
Iff. I One of the earliest studies showing
the linkages between the agricultural and
non-agricultural sectors was done at the
village level by Hayami while at IRRI
(Hayami et al. 1978). Hayami provides the
best micro-level illustration of the impacts of
rapid growth in rice production on land and
labor markets and the non-agricultural
sector. More recent assessments on the
impacts of productivity growth on land and
labor markets have been done by Pinstrup-
Andersen and Hazell (1985) and by David
and Otsuka (1994). Pinstrup-Andersen and
Hazell argued that landless laborers did not
adequately share in the benefits of the Green
Revolution because of depressed wage rates
attributable to migrants from other regions.
David and Otsuka, on the other hand, found
that migrants shared in the benefits of the
Green Revolution through increased
employment opportunities and wage
income. The latter study also documented
that rising productivity caused land prices
to rise in the high-potential environments
where the Green Revolution took off.
An IFPRI study by Hazell and Ramaswamy
(1991) showed the development of
backward and forward linkages from
increased agricultural productivity growth
in India. The term "backward linkages"











refers to the demand for inputs used in a
new production activity, whereas "forward
linkages" refers to new processing
industries stimulated by the availability of
raw materials provided by the new
production activity. Delgado et al. (1998),
also at IFPRI, found similar evidence of
growth being stimulated in the non-
agricultural sector by growth in agricultural
productivity. The work by researchers at
IFPRI has provided strong empirical
support for the proposition that agriculture
does indeed act as an engine of overall
economic growth (Hazell and Haggblade
1993; Fan et al. 1998)




Impacts on the Research
System through Spillovers,
Training, and Networks

Research on the impacts of the CGIAR on
national public-sector research, technology
development, and human resource capacity
needs to be enhanced substantially.


Research Spillovers
CGIAR economists have made an
important contribution to increased
research efficiency through their work on
technological spillovers. It often takes a
long time for knowledge to be developed
through research and then adopted.
Typically, ten years pass from the initiation
of a research project to the dissemination of
research results. By borrowing research
results (e.g., plant lines or varieties) from
other countries, a country can shorten its
research time and contribute to increased
returns to research investments (Alston et
al. 1995).
Several attempts have been made to
identify and incorporate such spillovers in
research priority setting at the level of


Table 3. US benefits and costs (in millions of
1993 US$) from CGIAR wheat and rice research

Benefits and costs Wheat Rice

Present value of benefits 13, 653 1,042
Present value of costs 71 63
Benefit-to-cost ratio 190:1 17:1

Source: Pardey et al. (1996).


individual countries. Brennan (1986), while
at CIMMYT, measured the benefits to
Australian wheat breeding programs of
access to CIMMYT breeding materials.
Pardey et al. (1996) measured the benefits
to US wheat and rice production from
germplasm developed at CIMMYT and
IRRI (Table 3). Pardey and Wood (1994)
explicitly accounted for cross-border
technology spillovers in agricultural
research priority setting in Latin America.
Morris et al. (1994) conducted a similar
assessment for wheat research spillovers
from India to Nepal. Maredia and Byerlee
(1999) quantified spillover benefits for
wheat across agroecological boundaries-
in other words, they measured the
transferability of wheat varieties
developed for one production
environment (e.g., an irrigated
environment) to another (e.g., a rainfed
environment).


Training and Networks
The CGIAR has made immense
contributions to strengthening research
capacity in the national research systems
of developing countries, primarily by
building human capacity (through training
programs) and by improving the exchange
of information and technology (through
networks). Surprisingly little has been
done to measure the impact of CGIAR
investments in training and networking. A
recent CIMMYT study of the Regional
Maize Program in Central America (a
maize research network) found high











returns to participation in the network,
especially for small countries that could
not afford a critical mass of crop research
and development specialists (G6mez
1999). Substantial work is needed on the
economic and social returns to network
participation, since this mode of linking
researchers in national programs and the
CGIAR is expected to continue into the
foreseeable future. Measuring the impacts
of networks is very difficult, however,
because of problems in clearly identifying
inputs and outputs and attributing them
to the participants in the network.
Training is another area in desperate need
of a critical impact assessment. Most
CGIAR Centers have counted numbers of
course participants and assembled
anecdotal information on training, but to
date no detailed impact assessment has
been done. Perhaps the recent SPIA effort
to evaluate the impact of CGIAR training
will fill this large gap.


Concluding Remarks

Over the past three decades, CGIAR
economists have been actively involved in
assessing the adoption and impact of MVs
and other technologies developed by the
CGIAR Centers. Impact assessment at the
CGIAR has been recognized for its
substantive and methodological
contributions by the economics profession
as well as by the donor community that
invests in the CGIAR Centers. The scope
of impacts work done at the centers has
expanded from a narrow effort to measure
the adoption of MVs to research
quantifying a wide array of impacts on
production, productivity, equity, human
health, and the environment. Numerous
high-quality publications in international
journals, as well numerous awards
received by CGIAR researchers, attest to
the high quality of the research conducted
at the centers. Even so, several concerns


remain to be addressed to enhance and
sustain the work that has been done, and
also to increase the impact of impact
assessment research.
While the scope of impact assessment
research in the CGIAR has expanded over
time, there continues to be a need (and
pressure) to further broaden the agenda of
impacts research. Evidence that modern
technology has contributed to poverty
alleviation is particularly sought after by
the donor community. Similarly, studies on
the impacts of agricultural modernization
on the sustainable management of
agricultural ecosystems in general, and
biodiversity in particular, are also in
demand. CGIAR economists have also
begun measuring the impacts of policy
research and advocacy, training and human
capacity strengthening, and networks for
technology generation and exchange. The
impact assessment community faces
enormous methodological challenges as it
gears up to measuring impacts in these
areas, but they are also the areas where
future milestones can be achieved.
Looking at the record of CGIAR impact
assessment research over the past three
decades, it is clear that not all centers have
been equally engaged in the work. A few
centers have had an outstanding record,
and many are trying to catch up. What
factors distinguish the few successful
centers from the rest?
It is likely that the commodity mandate of
some centers has made a big difference:
centers that achieved technological
breakthroughs with enormous impacts also
conducted outstanding impact assessment
research. Equally important was the value
that center leadership placed on building
and sustaining economics research
capacity. It is perhaps not coincidental that
centers with excellent impact assessment
credentials also supported an independent
economics group with a critical mass of











well-trained staff. The experience of the last
three decades has shown that there are no
shortcuts to sustainable, high-quality
performance in impact assessment research.
To maintain professional credibility and
ensure high-quality research, it is important
that the methods used in impact assessment
are the best available and that the work is
done in as transparent a manner as possible.
The most effective means for centers to
sustain the reputations of their impact
assessment groups over the long term has
been to constantly subject research results to
peer review. The long-term publicity value
of high-quality impact assessment research
cannot be underestimated and ought not be
sacrificed for short-term gains.
Although CGIAR economists have a good
record in impact assessment research, their
ability to communicate their results to a
wider audience has been rather poor.
Publication in high-quality journals is an
essential means of maintaining professional
credibility, but the findings of impact
research may have their true impact on an
audience that does not necessarily obtain its
information from professional economics
journals, such as taxpayers, development
assistance agencies, and philanthropic
organizations. Multiple and targeted


outputs derived from a set of results would
go a long way in helping to achieve the
goals of certain audiences while enhancing
the mission of the research institution.
It is also very important to recognize that
long-term credibility in impact assessment
research can be maintained only when the
inputs and contributions of all partners are
appropriately acknowledged. Many CGIAR
technologies are joint products that require
significant input from national program
partners and increasingly from the private
sector. It is sometimes unclear whether the
CGIAR can claim exclusive or even partial
credit for certain impacts. The nature of the
contribution ought to be specified clearly, be
it discovery, development, or facilitation.
Finally, there is a fine line between impact
assessment research and public awareness
activities. As noted above, impact results
certainly ought to reach a wider audience,
but it must be remembered that the primary
function of impacts research is to provide
feedback to researchers and to the
institution about what is going right and
what is going wrong with research and
development activities. The opportunity for
introspection and mid-course correction is
often lost when the balance is tipped too
heavily-or prematurely-towards the
publicity value of the results.














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Impact Assessment Studies

Conducted in the CGIAR, 1970-1999:

An Annotated Bibliography

Matthew P. Feldman

Note: This bibliography covers many, although not all, of the studies cited in this publication.
Readers interested in more detailed information on the studies that do not appear in this bibliography
are encouraged to consult the authors of those studies or the original publications themselves.


Antle, J.M., and P.L. Pingali. 1994.
Pesticides, productivity, and farmer health:
A Philippine case study. American Journal
of Agricultural Economics 76(3): 418-30.
Rice farmers from two regions in the
Philippines were interviewed to obtain data
for an analysis on human health and
productivity tradeoffs from limited
pesticide use. Through the models utilized
in this paper, it is determined that
"pesticide use has a negative effect on
farmer health, [and] that farmer health has a
positive effect on productivity." After
examining the health of the sample farmers,
Antle and Pingali used regression analysis
to estimate the cost of health treatments and
the opportunity cost of lost labor from
pesticide-related illnesses. These results
were then compared with the change in
productivity from possible taxes on
insecticides and herbicides which would
affect incentives and ultimately reduce
pesticide use. Antle and Pingali conclude
that there are two probable solutions to the
problems of pesticide use on human health;
either restrict pesticide use through policy
measures such as taxes or, alternatively, find
different pest management methods that
involve the use of safer chemicals or no
chemicals at all.


Binswanger, H.P., and J.G. Ryan. 1977.
Efficiency and equity issues in ex ante
allocation of research resources. Indian
Journal of Agricultural Economics 32(3):
217-31.
This paper discusses the informational
components necessary to make effective
decisions regarding research resource
allocation. Two principal topics, efficiency
and equity, are thoroughly examined.
Related to efficiency, Binswanger and Ryan
present topics including returns to scale, the
advantages of private- and public-sector
research, and the effect of factor shortage on
research endeavors. In discussing equity,
the authors compare distribution of
technological gains between producers and
consumers, laborers and labor owners, and
differing regions. It is mentioned that
certain technologies are site-specific and
thus disproportionately benefit farmers or
laborers of particular regions.


Brennan, J.P. 1984. Measuring the
contribution of new varieties to increasing
wheat yields. Review of Marketing and
Agricultural Economics 52(3): 175-95.
In determining the consequences of varietal
change on production, Brennan explains
and evaluates three measures: (1) the index
of varietal newness, (2) the proportion of
area sown to recent varieties, and (3) the
index of varietal improvement. Brennan











describes each measure by explaining its
function, including the endogenous and
exogenous variables, its advantages, and its
limitations. An empirical example is
evaluated with data from Mitchell Shire in
southern New South Wales between 1950 and
1981. The author concludes that one's choice
of measure is critical since there is not a high
statistical correlation, in general, between the
results of each index.


Brennan, J.P. 1986. Impact of Wheat
Varieties from CIMMYT on Australian Wheat
Production. Agricultural Economics Bulletin
No. 5. Sydney: Department of Agriculture,
New South Wales.
Benefits from CIMMYT-based varieties
(CBVs) have been recognized around the
world in developed and developing
countries. In this analysis, Brennan evaluates
the benefits and impact of CBVs of wheat
that are commercially cultivated in Australia.
He assesses the advantages of CBVs in
increasing yields, quality, disease resistance,
and their adoption by region, variety, type,
class, and grade. Additionally, he conducts
an extensive quantitative analysis of the
estimated benefits of CBVs by Australian
states between 1974 and 1983. Brennan
emphasizes the high adoption rates of
CIMMYT-based wheat varieties throughout
Australia and concludes that the benefits of
CBVs in Australia have been profound since
the 1960s.


Byerlee, D., and P. Moya. 1993. Impacts of
International Wheat Breeding Research in the
Developing World, 1966-90. Mexico, D.F.:
International Maize and Wheat Improvement
Center (CIMMYT).
Since the Green Revolution, the area planted
to modern varieties (MVs) has steadily
increased throughout the developing world.
Byerlee and Moya conducted an extensive
analysis of data from 38 developing countries
that included data on the area planted to


modern wheat varieties, percentage of
adopted varieties from CIMMYT
germplasm, and the benefits of CIMMYT
research during the post-Green Revolution
period of 1977-90. The authors estimate that
of the 600 varieties released in the
developing world between 1966 and 1990,
75% came directly from CIMMYT crosses or
were the result of crosses with CIMMYT
parents by national agricultural research
systems (NARSs). The new varieties
embodied many benefits, including yield
gains and disease resistance, which helped
CIMMYT to obtain a 54% internal rate of
return on its investment. In conclusion, the
authors emphasize that additional research
will need to focus on improving grain
quality and preserving genetic diversity.


Byerlee, D., and E. Hesse de Polanco.
1986. Farmers' stepwise adoption of
technological packages: Evidence from the
Mexican altiplano. American Journal of
Agricultural Economics 68(3): 519-27.
The adoption of inputs, either in a stepwise
manner or as a package, is dependent upon
the relative profitability of each input and
not solely on yield increases. Byerlee and
Hesse evaluate the adoption of improved
barley varieties, fertilizer, and herbicides in
two regions in Mexico between 1975 and
1980-a dry region with an annual rainfall
of 450-550 mm and a wet region with
annual rainfall of 600-700 mm. Their results
emphasize that the three inputs studied are
not perfect complements in production,
even though interaction between inputs
does exist, and thus are frequently adopted
in a stepwise fashion to minimize risk.


Byerlee, D., and M. Morris. 1993.
Research for marginal environments: Are we
underinvested? Food Policy 18(5): 381-93.
As remnants of the Green Revolution for
wheat are seen today through relatively
high yields in the developing world,











research has begun to focus on the disparity
between the benefits of research for
irrigated lands and "marginal"
environments plagued by poor water
control. By simply recognizing the low
adoption rates of modern varieties and low
yields in marginal environments, people
often believe that more investment is
needed in this area. As Byerlee and Morris
explain, the focus on marginal regions must
correspond with the value of the crop from
that locale. Background information,
including possible reasons for why more
resources should be placed on research for
marginal areas and reasons for low
adoption of modern varieties in marginal
environments, is presented along with a
model to determine over and
underinvestment. By using a congruency
model, the authors find that CIMMYT's
wheat breeding program and India's
research on wheat were not marked by
underinvestment in research for marginal
regions.


Crissman, C.C., J.M. Antie, and S.M.
Capalbo (eds.). 1998. Economic,
Environmental, and Health Tradeoffs in
Agriculture: Pesticides and the Sustainability
of Andean Potato Production. Boston:
Kluwer Academic Publishers.
In this book, the authors use data from the
Carchi Province of Ecuador to quantify the
impact of pesticide use on potato
production, on the environment, and on
human health. The book addresses the
demographics of the study region, the
methods of assessing environmental and
human health impairments, the effect of
government policies and exchange rates on
pesticide use, and simulation models
incorporating the environment, human
health, and economic tradeoffs. The authors
determine that a ban on pesticide use is not
a likely solution; a more probable solution
to the problem would be achieved by


improving farmer safety measures and
application strategies, as well as restricting
pesticide use. The models in this book
provide a quantitative framework to
illustrate the tradeoff between productivity,
farmer health, and environmental factors.


Dalrymple, D.G. 1977. Evaluating the
impact of international research on wheat
and rice production in the developing
nations. In T.M. Arndt, D.G. Dalrymple,
and V.W. Ruttan (eds.), Resource
Allocation and Productivity in National and
International Agricultural Research.
Minneapolis: University of Minnesota.
This early study of the impact of rice and
wheat research in the developing world
estimates changes in yield and area as well
as the role of high-yielding varieties (HYVs)
on these changes. It gives background
information on the International Maize and
Wheat Improvement Center (CIMMYT) and
the International Rice Research Institute
(IRRI), two initial centers of the
Consultative Group on International
Agricultural Research (CGIAR). Topics
include the direct and indirect effects of
HYVs, the gap between yields in research
plots and farmers' fields, changes in areas
sown to HYVs and crop yield, as well as the
effects of innovative technologies on rice
and wheat production in developing
countries. Two methods are used to
determine the impact of new technologies:
production function and index number
analyses. The implications and limitations
of these methods are described prior to
estimations of the value of increased output
in the early 1970s, principally in Asia. The
analysis concludes by emphasizing the
importance of impact research in
demonstrating the benefits of agricultural
research.











Dalrymple, D.G. 1978. Development and
Spread of High-Yielding Varieties of Wheat
and Rice in the Less Developed Nations.
USDA Foreign Agricultural Economics
Report No. 95. Washington, D.C.: United
States Department of Agriculture (USDA).
During the 12-year period of the Green
Revolution (1965/66-1976/77), the area
planted to high-yielding varieties (HYVs) of
rice and wheat in developing countries
greatly increased. This paper presents
information on the origins of semidwarf
wheat and rice varieties and the
development of many HYVs by the
International Maize and Wheat
Improvement Center (CIMMYT) and the
International Rice Research Institute (IRRI).
A vast majority of the data regarding area
planted to HYVs is a reflection of the area
planted to varieties supplied directly from
CIMMYT or IRRI or having CIMMYT or
IRRI parents. In the case of high-yielding
wheat, data on area planted to HYVs in
specific countries over all (or portions) of
the 12-year period are presented for Asia,
the Near East, Africa, and Latin America. In
the case of high-yielding rice, data on area
planted are available for Asia, the
Communist nations of Asia (Lao PDR,
People's Republic of China, and Vietnam),
the Near East, Africa, and Latin America. In
a more aggregate form, the results show
that about 19.7 million hectares of HYV
wheat and 24.2 million hectares of HYV rice
were planted in developing countries in
Asia (excluding Communist nations and
Taiwan) during 1976-77, making Asia the
predominant adopter of HYVs compared to
other regions in the developing world. The
total area of HYVs of wheat and rice in
developing countries (excluding
Communist nations, Taiwan, Israel, and
South Africa) in 1976-77 was 29.4 million
hectares and 25.3 million hectares,
respectively.


Dalrymple, D.G. 1986. Development and
Spread of High-Yielding Rice Varieties in
Developing Countries. Washington, D.C.:
United States Agency for International
Development (USAID).
This publication provides estimates of the
area planted to high-yielding rice varieties
(HYRVs) from the mid-1960s to the mid-
1980s in four geographical regions-South
and East Asia, the Near East, Africa, and
Latin America, and in 67 developing
countries. Dalrymple presents specific time-
series data for a few countries in South and
East Asia, where HYRVs are widely
adopted and data are more often available,
and for a few countries in Latin America.
Country details related to area planted in
selected years and the choice of rice
varieties are presented for other countries in
the study. The aggregate area planted to
HYRVs in developing countries in the four
regions, excluding communist nations and
Taiwan, was about 39.2 million hectares in
1982/83. When communist nations were
included (excluding North Korea), the
figure rose to 72.6 million hectares.


David, C.C. 1976. Fertilizer demand in the
Asian rice economy. Food Research Institute
Studies XV(1).
Using aggregate data from 11 Asian rice-
growing countries and two farm surveys
(one from the Philippines, Indonesia,
Thailand, Malaysia, India, and Pakistan,
and the other from Laguna, Philippines),
David presents a highly quantitative
analysis of fertilizer demand functions.
Determinants such as rice yield, fertilizer
use, fertilizer-rice price ratio, and price
elasticities are evaluated. The author studies
the dissemination of modern varieties, the
quality of the environment and irrigation
systems, productivity of fertilizers, and the
fertilizer-rice price ratio in explaining
varying consumption of fertilizer across
countries and within regions.











David, C.C., and R. Barker. 1978. Modern
rice varieties and fertilizer consumption. In
International Rice Research Institute (ed.),
Economic Consequences of the New Rice
Technology. Los Banos: International Rice
Research Institute (IRRI).
As land resources become more scarce and
populations continue to grow, the ability of
modern rice varieties (MVs) to respond to
fertilizer application has become increasingly
important. In this quantitative analysis of
factors contributing to varying fertilizer
consumption, the authors use three datasets:
one aggregate set from 12 Asian countries,
one farmer survey from six Asian rice-
growing countries, and one farmer survey
from Laguna, Philippines. Before presenting
the results of their analysis, the authors
compare MV and traditional variety (TV)
responsiveness to fertilizer applications.
Then the datasets are used to estimate
fertilizer demand functions for Asian rice-
growing countries. By using two demand
models, the authors derive the relative
contributions of the fertilizer-rice price ratio,
percentage of area planted to MVs, quality of
irrigation, output value, and quality of the
environment in explaining the gap between
average and high levels of fertilizer
consumption. The Asian aggregate data and
Laguna farmer data show that MV adoption
is a principal factor in explaining the gap
between average and high levels of fertilizer
use. The fertilizer-rice price ratio also
explains a large portion of the differences in
fertilizer use in all three datasets.


David, C.C., V.G. Cordova, and K. Otsuka.
1994. Technological change, land reform, and
income distribution in the Philippines. In C.C.
David and K. Otsuka (eds.), Modern Rice
Technology and Income Distribution in Asia.
Boulder: Lynne Rienner.
Through a highly quantitative analysis of
income distribution in the Philippines
between favorable and unfavorable cropping
environments, the authors evaluate the


factors that influence a distinct income
differential. In part because of a focus on
improving varieties for irrigated and
favorable rainfed regions, the productivity
gap between regions increases. Regression
analysis is utilized to determine the effect of
farm size, land tenure, ownership of capital,
and technological factors on income. Non-
rice income proved to be the most important
form of income leading to the income
difference between favorable and
unfavorable environments. In conclusion, the
authors recommended that emphasis be
given to increasing human capital and
improving research on rice for unfavorable
environments to decrease the inequality.


Doss, C.R. 1999. Twenty-Five Years of
Research on Women Farmers in Africa:
Lessons and Implications for Agricultural
Research Institutions; with an Annotated
Bibliography. CIMMYT Economics Program
Paper No. 99-02. Mexico, D.F.: International
Maize and Wheat Improvement Center
(CIMMYT).
Even though broad, definitive
generalizations cannot be made on why
enhanced agricultural innovations are not
quickly adopted by female African farmers,
this review of a wide array of literature helps
to clarify a few potential possibilities.
Important questions are raised in this study
and potential answers are given for specific
regions, but few generalizations for Africa as
a whole are presented. Doss emphasizes that
lack of access to labor, land, credit, fertilizer,
extension, and mechanization are some
potential reasons for the lack of use of new
maize technologies. Specific cases from
regions of Africa help illuminate the diversity
in gender issues. The author cautions that the
gender situation is continually changing and
thus it is important to conduct before and
after research on technology adoption. The
review is supplemented by a comprehensive
annotated bibliography for over 175
references on gender issues and African
agriculture.











Echeverria, R.G. 1990. Assessing the
impact of agricultural research. In R.G.
Echeverria (ed.), Methods for Diagnosing
Research System Constraints and Assessing
the Impact of Agricultural Research. Vol. II:
Assessing the Impact of Agricultural
Research. The Hague: International Service
for National Agricultural Research (ISNAR).
Echeverria reviews more than 100 studies
estimating rates of return to various crops
throughout the developed and developing
world. He emphasizes that impact
assessment has changed over the last few
decades as ex post and ex ante research have
started to move beyond general cost-benefit
studies of innovative technology. Current
research has begun to focus on spillover
effects, distribution of benefits and income,
government intervention in agriculture, and
the effects of agriculture policy. Echeverria
emphasizes that high rates of return for
agricultural research signify
underinvestment in this area. Following this
introduction, the first half of the book
focuses on issues such as the consequences
of omitting private-sector research,
measurement of changes in consumer-
producer surplus resulting from quality
improvement, and other topics. The second
half of the book contains more site-specific
case studies addressing research and
extension in Peru, and expected returns to
pasture improvement in Latin America.


Echeverria, R.G., G. Ferreira, and M.
Dabezies. 1991. Returns to Investment in the
Generation and Transfer of Rice Technology
in Uruguay: The Case of Rice. ISNAR Staff
Notes 89-50(s). The Hague: International
Service for National Agricultural Research
(ISNAR).
In this study of rice production in Uruguay
between 1965 and 1985, the authors give a
historical account of rice in the country
before estimating returns from technological
change. Even though there are many
components that must be accounted for in


technological change, this study includes
public and private extension and private
research. This analysis gives background
information including the area, production,
and yield of rice for Uruguay from 1931 to
1988, rice exports from 1973 to 1986,
countries importing rice from Uruguay, and
rice prices between 1981 and 1987. In
addition, it is determined that the rate of
return to research and extension investment
between 1965 and 1985 in Uruguay was 52%,
while the benefit-cost ratio was 5.5. The
authors also determine that producers
captured a large portion of the benefits from
research and extension. In conclusion, special
emphasis is placed on the concept of spillins,
as countries such as Uruguay must be able to
investigate, study, and introduce genetic
materials and management techniques from
other countries to realize high rates of return.


Evenson, R., and C. David. 1993.
Adjustment and Technology: The Case of
Rice. Development Centre Studies. Paris,
France: Organisation for Economic
Cooperation and Development (OECD).
During a time of market liberalization,
privatization, and structural reform in many
countries recovering from the financial crises
of the 1980s, Evenson and David emphasize
that "for inherently public good activities
such as rice research the invisible hand of the
market is not relevant." They believe that
privatization of rice research cannot take the
place of public research. In addition to
presenting information on past rice
consumption and production, the use of
genetic resources, distribution of benefits
from research, and investment issues, the
authors evaluate the effects of
"mismanagement" crises from the 1980s on
rice research. Following the crises, many
governments moved in support of market
economies in their efforts to bring about
structural reform in the public system. From
the available data, it is believed that the
"effectiveness" of rice research did not
change during the 1980s, but investment in











research declined in several countries which
have not seen an equal increase during the
reform era.


Fan, S., P. Hazell, and S. Thorat. 1998.
Government Spending, Growth, and Poverty:
An Analysis of Interlinkages in Rural India.
EPTD Discussion Paper No. 33. Washington,
D.C.: International Food Policy Research
Institute (IFPRI).
Since the mid-1960s, the number of people
living below the poverty line in India has
dropped dramatically. For this trend to
continue, it is important to evaluate the
marginal impact of various government
expenditures geared toward achieving a
reduction in poverty. The authors use a
simultaneous equation model to determine
which factors can provide the greatest impact
on rural poverty reduction and agricultural
productivity growth. Government
expenditures studied include the impact of
rural roads, agricultural research and
development, irrigation, rural electrification,
and education. Through estimates of
elasticities and numbers of people who
would be brought above the poverty line by
marginal expenditures, it is determined that
additional government expenditure on rural
roads would provide the greatest impact on
rural poverty. On the other hand, additional
expenditure on agriculture research and
development would provide the greatest
impact on growth in agricultural
productivity.


Flinn, J.C., and D.P. Garrity. 1989. Yield
stability and modern rice technology. In J.R.
Anderson and P.B.R. Hazell (eds.),
Variability in Grain Yields: Implications for
Agricultural Research and Policy in
Developing Countries. Baltimore: Johns
Hopkins.
This paper looks at the effects of modern rice
varieties and related technologies on
production stability in Asia. Factors such as


irrigation, cropping intensity, area, and
pesticide and fertilizer use are analyzed in
relation to their effect on production
stability. A small case study of Luzon and
Mindanao, Philippines, between 1974 and
1978 is used to illustrate some comparisons
of the variability of production based on
water control and varieties. In addition, the
authors explain the importance of
protecting diversity and developing
effective crop and soil management
strategies.


Franzel, S., D. Phiri, and F. Kwesiga.
1999. Assessing the adoption potential of
improved fallows in Eastern Zambia. In S.
Franzel and S. Scherr (eds.), Trees and
Farmers: Assessing the Adoption Potential
of Agroforestry Practices in Africa.
A five-year improved fallow and maize
rotation plan has rapidly become a popular
method of cropping in regions of eastern
Zambia. The improved fallow technique
involves planting trees for two years to
help rejuvenate the soil before planting
three consecutive years of maize. Franzel,
Phiri, and Kwesiga attempt to evaluate the
advantages and disadvantages of this
system compared to continuous plantings
of unfertilized or fertilized maize. They
find that over the five-year period, higher
returns to land and labor accrued to the
improved fallow technique over the
unfertilized maize pattern, while the
returns to labor were higher for the
improved fallow method than the
continuous fertilized maize technique.
Although under certain conditions the
benefit difference between improved
fallow and fertilized maize is not stark, it
must be emphasized that the relationship
in benefits between these two methods
depends greatly on the prices of maize and
fertilizer. Over the five-year cycle, fertilized
maize has the highest overall yield.











Flores-Moya, P., R.E. Evenson, and Y.
Hayami. 1978. Social returns to rice research
in the Philippines: Domestic benefits and
foreign spillover. Economic Development
and Cultural Change 26(3): 591-607.
In this paper the authors estimate the
benefit/cost ratio, internal rates of return,
supply and demand elasticities, and
spillover effects of rice research in the
Philippines. A review of past rice research
in the Philippines precedes a description of
the methodology used to calculate social
returns and the actual calculations. Factors
such as price elasticities, research costs at
international and national research facilities
in the Philippines, and the shift in the rice
production function owing to technological
innovation are quantified. The estimation
section shows that in a closed economy and
in the tropical world as a whole, consumers
reap the rewards of research, whereas
producers fare worse than prior to the
research. It is estimated that on average
every dollar invested in research in the
Philippines translates into a benefit of US$ 4
to the Philippines. Additionally, the
benefit/cost ratio is much higher for the
tropical world, which illustrates the impact
of spillover effects.


G6mez, M.I. 1999. Economic Benefits of
Research Cooperation: The Case of the
Regional Maize Program for Central America
and the Caribbean. Ph.D. thesis, University
of Illinois, Urbana-Champaign, Illinois.
Over the past decade, research on impact
assessment has begun to include spillover
effects. When these effects are not taken into
account, estimates of returns to investment
and thus financial resource allocation can
often be skewed. This award-winning thesis
describes and analyzes the sources of the
vast benefits of the cooperative breeding
program of the Programa Regional de Mafz
(PRM, or Regional Maize Program) in
Central America and the Caribbean. The
author identifies and quantifies spillovers


within the region and conducts cost-benefit
analyses on public breeding research.
G6mez estimates that close to two-thirds of
the maize research impact in the study area
comes from spillins from outside the region.
For the majority of countries in the region, it
is more beneficial to invest in the PRM than
in national agricultural research. Investment
in the PRM opens the door to receiving
large spillin benefits from the collaborative
international effort, which can capitalize on
specialization and returns to scale.


Hayami, Y., and R.W. Herdt. 1977.
Market price effects of technological change
on income distribution in semisubsistence
agriculture. American Journal of Agricultural
Economics 59(2): 245-56.
Hayami and Herdt emphasize the need for
technological innovations to shift the
supply function at a faster rate than the
shift in the demand function. Through a
study of rice variety innovations in the
Philippines, the authors quantitatively
analyze the income distribution between
sectors and within the rural sector using a
model they develop. Estimated factors
include changes in consumer surplus,
producer income, and income distribution
between large- and small-scale farmers for
both fixed and variable consumption of this
semisubsistence crop. In concluding, the
authors state that more equality can be
reached if innovations shift the supply
function faster than the demand function,
allowing prices to fall.


Hazell, P.B.R., and C. Ramaswamy. 1991.
The Green Revolution Reconsidered: The
Impact of High-Yielding Rice Varieties in
South India. Baltimore: Johns Hopkins.
In this series of papers on the effects of the
Green Revolution in rice in North Arcot
District of South India, Hazell and
Ramaswamy show that the rural poor
received both direct and indirect benefits











from the technological innovations. Initially
the new technology was adopted
principally by large-scale farmers, but as
time passed smaller farms began adopting
high-yielding varieties at similar rates as
large-scale farmers. It is estimated that new
technology increased rice output, lowered
poverty, improved diets, and positively
affected the non-farm economy, without
leading to broad changes in the number of
landless people in adoption regions.
Between 1973-74 and 1983-84 "small paddy
farmers and landless laborers gained the
largest proportional increases in family
income." The authors point out that the
results of these papers are quite different
from those of previous studies, which
evaluated the new technology too early in
the adoption process. Since many studies
were conducted too early, some concluded
that the new technology was not scale-
neutral, had fostered inequality, and had
resulted in disproportionate gains by large-
scale farmers.


Herdt, R.W. 1987. A retrospective view of
technological and other changes in Philippine
rice farming, 1965-1982. Economic
Development and Cultural Change 35(2):
329-49.
In response to reports stating that
innovative technology was principally
utilized by large-scale farmers, Herdt uses
case studies from central Luzon and
Laguna, Philippines, over a 15-year period
to show that adoption of modern rice
varieties was relatively independent of
scale. In Laguna there was no significance in
adoption based on farm size. In the Luzon
sample, on the other hand, small-scale
farmers' adoption of the new technology
was slower in the beginning, but at the end
of the study period there was no difference
in adoption rates between small- and large-
scale farmers. Data indicate increases in
production from 1966 to 1982, labor use per
hectare, double cropping, the use of power
tillers, and the use of fertilizer and


irrigation. In addition, many farmers
switched from sharecropping to
leaseholding. Even though there were large
increases in yields, farmers' real incomes did
not change dramatically because of large
increases in production costs. Thus, during
the study period, real rice prices were
depressed and consumers were the principal
beneficiaries of technological change.


Herdt, R.W., and C. Capule. 1983.
Adoption, Spread, and Production Impact of
Modern Rice Varieties in Asia. Los Banos:
International Rice Research Institute (IRRI).
In this report, the authors discuss adoption
of modern rice varieties (MVs) in South and
Southeast Asia, increased production since
1965, and factors correlated with adoption.
The authors describe adoption, key players,
IRRI's role in the changes, percentage of area
planted with MVs, and land categories in 11
countries: Bangladesh, Burma, India,
Indonesia, the Republic of Korea, Malaysia,
Nepal, Pakistan, the Philippines, Sri Lanka,
and Thailand. Modern rice varieties were
adopted most rapidly in the Philippines,
with 89% of irrigated rice land and 77% of
rainfed rice area planted to MVs in 1979-80.
In addition, the authors discuss previous
regression analyses of variables related to
adoption of MVs and fertilizer, including
age, schooling, technological knowledge,
social class, and family size, and factors that
influence variable costs, including farm size,
tenure, wealth, fertilizer, and credit
availability.


Herdt, R.W., and A.M. Mandac. 1981.
Modern technology and economic efficiency
of Philippine rice farmers. Economic
Development and Cultural Change 29(2):
375-99.
With data from Nueva Ecija, Philippines,
between 1974 and 1977, Herdt and Mandac
attempt to determine factors which lead to
the yield gap between potential and realized











on-farm rice yields. Even though semidwarf
varieties have proven to have relatively
high yield capability on experiment stations
compared with traditional varieties, these
vast benefits have not been entirely realized
on the farm. The authors determine that
three factors-profit-maximization attitudes,
allocative inefficiency, and technical
inefficiency-contribute to the yield gap and
then quantify the relative effect of each
factor on the yield discrepancy. After
estimating production functions for each
farm and utilizing regression analysis, they
conclude that farm size, information, and
number of days off the farm are three
principal contributors to the economic
inefficiency. Herdt and Mandac find that
farm size is negatively related with
efficiency (i.e., larger farms are less
efficient), whereas information and days off
the farm are positively related to efficiency.


Herdt, R.W., and T.H. Wickham. 1978.
Exploring the gap between potential and
actual rice yields: The Philippine case. In
International Rice Research Institute (ed.),
Economic Consequences of the New Rice
Technology. Los Banos: International Rice
Research Institute (IRRI).
Even though modern rice varieties (MVs)
have been exalted as having potential yields
of between 6 and 10 t/ha, these lofty
expectations have not been realized in
farmers' fields: a 1969-70 study in the
Philippines found yields of irrigated MVs to
be 2.1 t/ha. This paper attempts to discover
reasons for the gap in rice yields on
experiment stations and in farmers' fields.
The authors begin with an analysis of data
from an IRRI experiment on rice variety
IR20 and estimate the "maximum attainable
national average yield" for the Philippines
is 4.1 t/ha, taking into account climatic,
water, and environmental conditions. The
principal explanation for the yield gap is
the motivation of farmers to maximize
profits more often than yields. The authors


explain that farmers must take factors such
as risk and diminishing returns into
consideration. Of eight input use scenarios,
three result in the maximum yield
delivering the maximum profit, while five
demonstrate that yields below the
maximum can result in larger profits. In
conclusion, Herdt and Wickham state that
water control, solar radiation, season, risk
and other economic determinants, yearly
variations, and insect, disease, and weed
damage are the principal factors accounting
for the vast difference between actual and
potential yields of modern rice varieties.
Thus efforts to diminish the yield gap must
focus on these research areas.


Hossain, M. 1998. Rice research,
technological progress, and the impact on
the rural economy: The Bangladesh case. In
P.L. Pingali and M. Hossain (eds.), Impact
of Rice Research. Proceedings of the
International Conference on the Impact of
Rice Research, 3-5 Jun 1996, Bangkok,
Thailand. Bangkok and Los Banos: Thailand
Development Research Institute (TDRI) and
International Rice Research Institute (IRRI).
Hossain chronicles agricultural research
efforts in Bangladesh and their progress
towards reducing poverty within the
country. He presents data on research
investment, education of researchers,
characteristics of modern varieties
developed for the country, and
dissemination of improved varieties. A
comparison of unit costs of rice production
between traditional and modern varieties
from 1973 to 1993 is presented, which
facilitates benefit-cost estimates of research
investment in rice. Estimates show that
when evaluating cost reductions in rice
production the benefit-cost ratio of
investment in production and technology
transfer is 16.6:1, but when one includes the
savings from a decline in food imports, the
ratio more than doubles to 36:1. Even











though it is frequently argued that benefits
of modern varieties accrue
disproportionately to large-scale farmers,
this study shows benefits to the poorer
segments of the population from reduced
rice prices and a reduction in poverty within
the country.


Islam, Y., and J.L. Garrett. 1997. IFPRI and
the Abolition of the Wheat Flour Ration
Shops in Pakistan: A Case-Study on
Policymaking and the Use and Impact of
Research. Impact Assessment Discussion
Paper No. 1. Outreach Division.
Washington, D.C.: International Food Policy
Research Institute (IFPRI).
Through research and dissemination of
results to government policymakers, IFPRI
was able to provide information which
eventually led, in part, to the abolishment of
Pakistan's wheat ration-shop system. The
authors explain IFPRI's five-stage research
program and its application to a case study
of the ration-shop system in Pakistan. The
five stages are: (1) client consultation and
research program design, (2) research
program implementation, (3) the
communication of research results,
(4) policymaking, and (5) impact
assessment. The case study emphasizes that
through close collaboration with key actors
inside and outside the government, IFPRI
was able to tailor the research to
policymakers' interests and provide this
information on a continual, timely basis
instead of through a final report, which was
not published until 1988. The subsequent
abolition of this ration-shop system was
due, in part, to a wasteful and corrupt
system which did not have a strong impact
on the poor population.


Litsinger, J.A. 1989. Second generation
insect pest problems on high yielding rices.
Tropical Pest Management 35(3): 235-42.
Recent advances in irrigation, modern
variety development, and increased
cropping intensity have put pressure on rice
yields as farmers now must battle pests that
no longer have a natural break in their
development cycles. With increased
cropping intensity there are no long fallow
periods in which the majority of the pests
die. The government recommended virulent
insecticides to kill pests, but the insecticides
also killed natural predators. Because of
these insecticides and year-round cropping,
pests have become more difficult to control.
Litsinger recommends that communities set
timetables for the crop season to provide
some fallow time and develop integrated
pest management (IPM) strategies.


Lopez-Pereira, M.A., and M.L. Morris.
1994. Impacts of International Maize
Breeding Research in the Developing World,
1966-1990. Mexico, D.F.: International
Maize and Wheat Improvement Center
(CIMMYT).
In this analysis of the adoption of improved
maize varieties and hybrids in the
developing world between 1966 and 1990,
L6pez-Pereira and Morris use data from 45
countries to estimate the area planted to
improved varieties and CIMMYT's
contribution to the development of those
varieties. The authors estimate that in 1990,
24.6 million hectares of land in developing
countries, or 43% of the area planted to
maize, was planted to improved maize.
Since 57% of the area in developing
countries planted to maize was planted to
unimproved varieties, there is opportunity
for further dissemination of improved
varieties and hybrids. Of the 24.6 million
hectares of improved maize, 13.5 million
hectares were planted to improved maize
containing CIMMYT germplasm. Between











1966 and 1990, 53% of the 842 maize
varieties and hybrids released by public
breeding programs in developing countries
contained CIMMYT germplasm. In addition
to the aggregate analysis, the authors also
present a breakdown of countries in sub-
Saharan Africa, Asia, North Africa, and
Latin America, describing releases and area
under local and improved varieties.


Maredia, M.K., and D. Byerlee (eds.).
1999. The Global Wheat Improvement
System: Prospects for Enhancing Efficiency
in the Presence of Spillovers. CIMMYT
Research Report No. 5. Mexico, D.F.:
International Maize and Wheat Improvement
Center (CIMMYT).
This study of the efficiency of the
international wheat improvement system
attempts to evaluate the effects of spillovers
in developing countries. One principal topic
addressed is the decision to breed broadly
adapted varieties for vast arrays of
environments versus breeding site-specific
varieties. By including the effects of
research spillovers between programs, both
national and international, the authors
attempt to eliminate a bias in previous cost-
benefit analyses. After evaluating the effects
of spillover benefits, the authors conducted
an econometric analysis which found that
28 of the 69 research programs studied in
developing countries invested too much in
wheat improvement research. Many wheat
improvement programs in developing
countries are too large for their mandate
areas and would benefit from investing in
programs to screen varieties developed
elsewhere. Economic topics, including
economies of scale and scope, are addressed
as they apply to the comparative advantage
of various research programs. Case studies
from India and Australia are presented to
analyze actual spillover effects and returns
to investment.


Mclntire, J., D. Bourzat, and P. Pingali.
1992. Crop-Livestock Interaction in Sub-
Saharan Africa. Washington, D.C.: The
World Bank.
In this comprehensive analysis of crop-
livestock interactions in sub-Saharan Africa,
the authors investigate the potential benefits
and limitations of integrating these two
agricultural components. To provide a well-
rounded study, evidence is obtained from
previous research on farming systems as
well as recent surveys from 33 African
locales. After describing the four climatic
regions-humid, subhumid, semiarid, and
highlands-the authors provide an overview
of crop-livestock interactions, the potential
for competition for scare resources, and
possible complementary effects. Issues such
as animal traction, soil fertility, crop residue,
and animal production are integrated into
the analysis prior to an overall evaluation of
policy recommendations. In conclusion, the
authors single out three obstacles to
increasing productive crop-livestock
interactions: (1) previous trade and
governmental policies working against
African agriculture, (2) scarcity of
information on profitable technology, and (3)
a lack of farming methods that are both
profitable and relevant to the regions of
Africa. It is determined that agricultural
growth will not dramatically change even if
constraints to crop-livestock integration are
alleviated; rather, exogenous technical
change should be implemented to help
expedite growth.


Morris, M.L., H.J. Dubin, and T. Pokhrel.
1994. Returns to wheat breeding research in
Nepal. Agricultural Economics 10(3): 269-
82.
Because Nepalese research institutes have
been established to test and spread
improved, imported wheat varieties
throughout the country, and because of
interaction between Nepalese and Indian
farmers, Nepal has achieved high internal











rates of return to wheat breeding research
during the Green Revolution (1965-90). The
authors estimate ex post returns to research
investment during the Green Revolution
and provide an ex ante estimate of future
returns to wheat breeding research (1990-
present). They find that the internal rate of
return was 84% during the Green
Revolution and predict it to be 49% in the
future. In conclusion, they acknowledge that
it may not be feasible for smaller countries
to conduct extensive breeding research, but
as the case of Nepal indicates, it is possible
to capitalize on spillover effects from
international centers and other countries to
achieve a relatively high rate of return.


Moya, T.B., W.C. de la Viha, and S.I.
Bhuiyan. 1994. Potential of on-farm reservoir
use for increasing productivity of rainfed rice
areas: The Philippine case. In S.I. Bhuiyan
(ed.), On-farm Reservoir Systems for
Rainfed Ricelands. Manila: International Rice
Research Institute (IRRI).
In this study of on-farm reservoirs (OFR)
in Central Luzon, Philippines, the
authors determine that constructing an
OFR provides good returns on the
investment and can be beneficial for
farms independent of scale. The paper
uses a case study from the 1985 wet
season to evaluate the benefits of an OFR.
They find that the average rice yield
differential between farms with an OFR
and rainfed farms is 0.5 t/ha. This
difference is compounded when one
considers that farmers using an OFR can
plant, on average, 40% of their farm area
during the dry season and obtain average
yields of 2.3 t/ha. Additionally, many
farmers use the OFRs to raise fish for
home consumption and sale. When
certain maintenance and life-span
characteristics of an OFR are accounted
for, the authors estimate the benefit-cost
ratio of OFRs to be 5.1.


Norgaard, R.B. 1988. The biological
control of cassava mealybug in Africa.
American Journal of Agricultural Economics
70(2): 366-71.
Cassava has been a crucial food source in
Africa since its introduction 300 years ago. A
mealybug was introduced to the continent
during the 1970s and caused large crop
losses during in the 1980s. Due to the ability
of international and national programs to
collaborate and capitalize on the
biodiversity of South America, a wasp,
Epidinocarsis lopezi, was found to be a
parasite of the cassava mealybug. Because
of the low-cost methods of finding,
reproducing, and disseminating this
parasite, the benefit-cost ratio has been
estimated to be 149:1. Empirical evidence
shows that measures to control pests
through biological means can lead to
relatively large benefit-cost ratios.


Palanisami, K., and J.C. Flinn. 1989.
Impact of varying water supply on input use
and yields of tank-irrigated rice. Agricultural
Water Management 15(4): 347-59.
Palanisami and Flinn use a simultaneous-
equation model to estimate the impact of
water supply on rice yields. With data from
southern India, the authors estimate the
impact of five inputs-tank water, well
water, nitrogen, labor, and crop
management-on rice yields during years
characterized by a water surplus and those
marked by a deficit. The model developed
in the study allows the authors to
numerically explain the factors which cause
the difference between low- and high-
yielding rice farms. During water-deficit
years, the calculated yield difference was
3.74 t/ha, caused principally by a lack of
water (60%) and inadequate crop
management (34%). During water-surplus
years, the calculated yield difference was
1.64 t/ha, caused principally by poor crop
management (57%).











Pardey, P.G., J.M. Alston, J.E. Christian,
and S. Fan. 1996. Hidden Harvest: U.S.
Benefits from International Research Aid.
Food Policy Report. Washington, D.C.:
International Food Policy Research Institute
(IFPRI).
Even though the principal focus of the 16
international agricultural research centers of
the Consultative Group on International
Agricultural Research (CGIAR) is to
alleviate hunger in developing countries
through increased food production, benefits
also accrue to developed countries. This
report presents results of a benefit-cost
analysis of the US government's research
investment in two CGIAR centers, the
International Maize and Wheat
Improvement Center (CIMMYT) and the
International Rice Research Institute (IRRI).
These centers conduct research on rice and
wheat, important crops for the US. The
authors estimate that the benefit-cost ratios
of US government financial investment in
CIMMYT and IRRI were 190:1 and 17:1,
respectively.


Paris, T.R. 1998. The impact of technologies
on women in Asian rice farming. In P.L.
Pingali and M. Hossain (eds.), Impact of
Rice Research. Proceedings of the
International Conference on the Impact of
Rice Research, 3-5 Jun 1996, Bangkok,
Thailand. Bangkok and Los Banos: Thailand
Development Research Institute (TDRI) and
International Rice Research Institute (IRRI).
As farming has become more efficient
through mechanization, discussion has
heightened regarding the benefits and
disadvantages of new technology on women
farmers. Paris emphasizes that to study the
positive and negative consequences of
technology, researchers must pay careful
attention to differences in socioeconomic
class among women farmers. Such groups
include female-headed houses, females in
landowning households, and landless


female laborers. Through an extensive
literature review it is determined that each
class of female farmers is affected
differently by new technology. This analysis
looks at various forms of technology,
including modern variety adoption,
mechanical reapers, direct vs. hand seeding,
rice mills, and herbicides to determine how
different classes of female farmers are
affected. As long as wages are high, landless
female laborers will experience numerous
negative consequences of technology
because their efforts are replaced by more
efficient technological innovations. On the
other hand, women from landowning
households experience both positive and
negative consequences, in which the net
result of new technology is still not
definitive.


Perrin, R.K., D.L. Winkelmann, E.R.
Moscardi, and J.R. Anderson. 1976. From
Agronomic Data to Farmer
Recommendations: An Economics Training
Manual. CIMMYT Information Bulletin 27.
Mexico, D.F.: International Maize and
Wheat Improvement Center (CIMMYT).
This economics text provides a framework
by which agronomists can learn to use
economic criteria to evaluate and make
farming recommendations. The authors
present a step-by-step process of finding a
similar set of plots for trials, estimating
costs of capital investments, determining
benefits and costs along with their
variability, and ultimately calculating the
expected rate of return. The authors
emphasize that factors such as risk and lack
of access to capital must be considered in
making recommendations to farmers. If the
return to the additional investment in a
technology is not at least 40%, then it
should not be recommended to farmers.
Special emphasis is placed on evaluating
benefits and costs of potential
recommendations at the margin and
considering opportunity costs. In











concluding, the authors present two
examples which help to apply the
procedures of evaluating a potential
recommendation.


Pingali, P.L., and R.V. Gerpacio. 1997.
Living with reduced insecticide use for
tropical rice in Asia. Food Policy 22(2):
107-18.
During the years following the Green
Revolution, insecticide use dramatically
increased in Asia. Pingali and Gerpacio
estimate that insecticide expenditures in
Asia increased from US$ 347 million to
almost US$ 1.1 billion between 1980 and
1990. This increase has led researchers to
study the returns to high insecticide use and
a "zero-insecticide strategy" as well as
practices that lie between these two
extremes. A study initiated in 1993 in the
Philippines showed that areas practicing a
zero-insecticide strategy had the highest
economic payoff; separate studies have
begun to corroborate this finding in other
regions of Asia. In determining which
method of insect control to use, one must
weigh the risks of possible pest infestations
from a lack of insecticide against the vast
array of health, environmental, and
ecological risks of insecticide use. The
authors believe that government subsidy
programs for insecticides should be
removed and replaced by taxes.


Pingali, P.L., C.B. Marquez, and F.G.
Palis. 1994. Pesticides and Philippine rice
farmer health: A medical and economic
analysis. American Journal of Agricultural
Economics 76(3): 587-92.
In a study of 152 rice farmers in the
Philippines, Pingali, Marquez, and Palis
evaluate the health effects of pesticide use.
Regressions are used to determine the
factors-including farmer traits such as
alcohol and tobacco consumption, pesticide


use, and age-that affect health. The
authors estimate the probabilities of having
eye, respiratory, gastrointestinal, dermal,
and neurological problems under several
input decisions. Estimates of health costs
range from 1,084 Philippine pesos for no
insecticide applications to the opposing
extreme of 2,792 pesos for roughly six
insecticide applications. When the health
impacts of pesticide use are taken into
account, it is more profitable for farmers not
to apply insecticide. As a result, the authors
recommend that there should be regulations
to reduce pesticide use and correspondingly
reduce the harmful effects on farmer health.


Pinstrup-Andersen, P., N. Ruiz de
Londoho, and E. Hoover. 1976. The impact
of increasing food supply on human nutrition:
Implications for commodity priorities in
agricultural research and policy. American
Journal of Agricultural Economics 58(2):
131-42.
In this paper the authors develop a
procedure to evaluate the relative priority
that should be given to research on specific
commodities to achieve increased calorie
and protein intake. They use data gathered
from an urban population in Cali,
Colombia, between 1969 and 1970. The
authors divide the sample into five income
categories and then analyze changes in
nutritional intake based on a supply
increase. They provide estimates of calorie
and protein intake, percentage of the supply
increase consumed by nutrient-deficient
categories, priority rankings for agricultural
commodity research based on calorie and
protein objectives, and price elasticities of
selected food products for each income
category. The authors point out that maize
is an extremely important means to increase
calorie and protein intake because its
priority level is in the top five for the tested
assumptions of supply elasticity and cost.











Quisumbing, A.R., L. Haddad, and C.
Pena. 1995. Gender and Poverty: New
Evidence From 10 Developing Countries.
Food Consumption and Nutrition Division
(FCND) Discussion Paper No. 9.
Washington, D.C.: International Food Policy
Research Institute (IFPRI).
Quisumbing, Haddad, and Pefia analyze
the relationship between gender and
poverty by using the stochastic dominance
method. The 10 countries studied are
Botswana, Cote d'Ivoire, Ethiopia, Ghana,
Madagascar, Rwanda, Bangladesh,
Indonesia, Nepal, and Honduras. After
explaining the method used to measure
gender differences, the authors discuss the
difficulties in classifying households into
male- and female-headed households. A
brief description of stochastic dominance
precedes the analysis. The authors find
only a few cases in which female-headed
households are worse off than male-
headed households, including cases from
rural Ghana and Bangladesh.


Renkow, M. 1993. Differential technology
adoption and income distribution in
Pakistan: Implications for research resource
allocation. American Journal of Agricultural
Economics 75(1): 33-43.
Renkow utilizes a multimarket model to
test income distribution under
technological innovation in Pakistan. The
paper begins with an overview of wheat in
Pakistan and the multimarket model. For
the analysis of income distribution,
Renkow divides the sample population
into small and large irrigated farms,
landless farmers, small and large rainfed
farms, and poor and rich urban dwellers.
The model is used to identify the principal
recipients of technological innovation
under various conditions. Renkow
concludes that when wheat prices are


controlled by the government, net-
producing households, which include large,
rainfed farms, and small and large irrigated
farms, are the primary recipients of
economic gains. When the market controls
prices, net-consuming households, which
include small, rainfed farms, landless
farmers, and the urban population, stand to
benefit the most from technological
innovations.


Rola, A., and P. Pingali. 1993. Pesticides,
rice productivity, and health impacts in the
Philippines. In P. Faeth (ed.), Agricultural
Policy and Sustainability: Case Studies from
India, Chile, the Philippines, and the United
States. Washington, D.C.: World Resources
Institute.
In this study, Rola and Pingali estimate the
net benefits of four insect control practices
in the Philippines when taking farmer
health into consideration. The four pest
management practices evaluated are:
(1) complete protection, (2) economic
threshold, (3) natural control, and
(4) farmers' practice. Initially, the benefits of
each treatment are estimated under several
climatic and market conditions. After
explaining health consequences of pesticide
use and comparing the number of cases of
certain illnesses in exposed and unexposed
villages, the authors calculate the expected
utility of each practice, taking health costs
into consideration. When health costs are
accounted for, the management practices
with the greatest to lowest net benefits are
the natural practice, farmers' practice,
economic threshold, and complete control.
The authors recommend that governments
restrict the use of the most hazardous
pesticides, thereby creating an incentive to
use safer chemicals.











Sain, G.E., and H.J. Barreto. 1996. The
adoption of soil conservation technology in
El Salvador: Linking productivity and
conservation. Journal of Soil and Water
Conservation 51(4): 313-21.
Combining productivity-enhancing and
soil-conserving techniques into one
recommendation proved successful in
Guaymango, El Salvador. Even though Sain
and Barreto give numerous possible reasons
why farmers in other parts of El Salvador
did not adopt the recommended method of
soil conservation when it was proposed 15-
20 years ago, they dedicate the majority of
the paper to emphasizing reasons why a
large proportion of Guaymango farmers did
adopt them. The authors explain how the
format of the program, which divided
farmers into groups and supplied credit
only to groups whose members followed
the entire recommendation, allowed for the
package recommendation to be widely
adopted. Empirical evidence shows that the
conservation component of the package
increased costs in the short run, but this
increase was offset by the strong benefits of
the productivity component.


Scobie, G.M. 1979. The demand for
agricultural research: A Colombian
illustration. American Journal of Agricultural
Economics 61(3): 540-45.
Scobie uses the case of rice in Colombia to
explain seemingly contradictory efforts of
government investment in agricultural
research and national policy to protect the
country's manufacturing industry. These
policies economically hurt the Colombian
rice industry by artificially altering the
exchange rate and affecting returns to
investment in several sectors. Scobie brings
political and economic issues together in
discussing funding for research and the
distribution of resulting benefits. Between
1957 and 1974, rice output increased
fivefold, thus lowering the domestic price
and benefiting consumers. Between 1968


and 1974, rice exports were minimal
because of an overvalued exchange rate. In
1975, rice prices fell enough to make
exporting a viable option. This change will
be evident in the distribution of benefits, as
producers and foreign consumers reap more
rewards from Colombia's agricultural
research.


Scobie, G.M., and R.T. Posada. 1978. The
impact of technical change on income
distribution: The case of rice in Colombia.
American Journal of Agricultural Economics.
60(1): 85-92.
This study is one of the earliest endeavors to
quantify the distribution of benefits of
semidwarf rice varieties in Colombia. After
a crippling virus affected rice production in
1957, the Colombian Ministry of
Agriculture, the Centro Internacional de
Agriculture Tropical (CIAT, the
International Center for Tropical
Agriculture), and the International Rice
Research Institute (IRRI) partnered to
develop a semidwarf variety resistant to the
virus. Instead of studying the rate of return
or efficiency of the new varieties, the
authors empirically studied the distribution
of benefits or equity to producers and
consumers as well as to income levels. This
pivotal research concluded that households
in lower income brackets received the
majority of the benefits of the research.


Sidhu, D.S., and D. Byerlee. 1992.
Technical Change and Wheat Productivity in
the Indian Punjab in the Post-Green
Revolution Period. CIMMYT Economics
Working Paper 92-02. Mexico, D.F.:
International Maize and Wheat Improvement
Center (CIMMYT).
Since the Indian Punjab accounts for
roughly one-quarter of Indian wheat
production, it is important to analyze past,
present, and future possibilities of











productivity growth. During the Green
Revolution, wheat production increased at a
rate of 10% per year in the Punjab. Today,
though, the increase is 4.8%. What has
changed over the past two decades? Is there
a possibility of future productivity growth in
the double digits? In this paper, Sidhu and
Byerlee document trends in input use, real
input and output prices, and productivity.
They find that while real wheat prices have
fallen, so have total production costs. In
addition, there has been a shift from using
organic manure and animal labor to
chemical fertilizers and tractors. In
conclusion, the authors explain that even
though farmers captured the majority of the
economic gains during the Green
Revolution, today consumers are receiving a
large share of the gains from reduced output
prices.


Smale, M. (ed.). 1998. Farmers, Gene
Banks, and Crop Breeding: Economic
Analyses of Diversity in Wheat, Maize, and
Rice. Boston: Kluwer Academic Publishers.
By presenting the results of initial economic
investigations of genetic diversity in the
three major food crops (wheat, maize, and
rice) in developing countries, this volume
furthers the understanding of the economic
context in which crop breeders make use of
genetic resources and their diversity. It
provides an annotated catalog of the tools
used to measure and value genetic diversity.
The book also explores fundamental
questions related to the value and efficiency
of conserving seed ex situ, in gene banks.
Several chapters analyze farmers' objectives
and incentives for conserving crop genetic
resources in centers of crop diversity (in
situ), offering procedures for monitoring,
predicting, and developing potential
mechanisms to encourage the conservation
of crop genetic resources in farmers' fields.
In addition, the book explores
methodological issues that are important for
studying the economics of crop species


diversity in farmers' fields, and it examines
how diversity is mediated by policies and
institutions.


Smale, M., R.P. Singh, K. Sayre, P.
Pingali, S. Rajaram, and H.J. Dubin. 1998.
Estimating the economic impact of breeding
nonspecific resistance to leaf rust in modern
bread wheats. Plant Disease 82(9): 1055-
61.
Using data from the Yaqui Valley in
northwestern Mexico from 1970 to 1990, the
authors estimate the economic benefit and
internal rate of return on the investment in
breeding for nonspecific resistance to leaf
rust in modern bread wheats. After
explaining the importance of maintenance
breeding, the authors quantify yield losses
that would have occurred if the varieties
had not been bred for nonspecific leaf rust
resistance. In conducting the analysis,
emphasis is placed on the benefits of
nonspecific resistance over specific leaf rust
resistance. Using costs of the International
Maize and Wheat Improvement Center's
(CIMMYT) pathology program, and
benefits to the Yaqui Valley between 1970
and 1990 of US$ 17 million, the authors
estimate rates of return under several
assumptions. The internal rate of return on
investment is 13% if a ten-year research lag
is present and almost 40% if a five-year lag
is present.


Traxler, G., and D. Byerlee. 1992.
Economic returns to crop management
research in a post-Green Revolution setting.
American Journal of Agricultural Economics
74(3): 573-82.
Despite numerous endeavors to conduct
studies of the impact of agricultural
research, crop management research (CMR)
has not received adequate attention. Traxler
and Byerlee emphasize the need to evaluate
an entire CMR portfolio instead of











individual projects, because the evaluation
of returns to individual projects can inflate
the benefits. Whereas the benefits of
breeding and actual manufacturing of
inputs can be quantified relatively easily, the
outputs of public sector research on crop
management consist largely of information
and knowledge, and their impact is much
more difficult to evaluate. From a case study
of the Yaqui Valley in northwestern Mexico
from 1977 to 1988, the authors find that only
two of nine practices developed by the CMR
program were adopted by farmers based on
recommendations of the local research
agency. Thus, despite individual project
returns of 50% and 100%, the return on the
entire CMR portfolio in this study was 16%.


Traxler, G., and D. Byerlee. 1993. A joint-
product analysis of the adoption of modern
cereal varieties in developing countries.
American Journal of Agricultural Economics
75(4): 981-89.
Although grain yield is the principal
criterion for evaluating the success of cereal
varieties, Traxler and Byerlee evaluate the
benefits of joint-product profit maximizing
in cereal production. Modern varieties
(MVs) are semidwarf and therefore have
small straw yields. In joint-product profit
maximization, the producer evaluates the
relative prices of grain and straw in
determining the payoff matrix to MVs and
traditional varieties (TVs). This paper
presents a model for evaluating joint-
product profit maximization under several
climatic conditions, during different periods
(the pre-Green Revolution, Green
Revolution, and post-Green Revolution
eras), and under varying relative input and
output prices. The authors conclude that
MV adoption is slowest in areas with low
rainfall where the grain yield differential is
not as dramatic between TVs and MVs and
the price of fodder is relatively higher.


Unnevehr, L.J. 1986. Consumer demand
for rice grain quality and returns to research
for quality improvement in Southeast Asia.
American Journal of Agricultural Economics
68(3): 634-41.
As the benefits of the Green Revolution are
seen through large supplies of rice,
researchers are recognizing the increasing
need to invest in quality-improvement
research. Unnevehr suggests that previous
research on physical-quality improvement
will now be followed by research on
chemical-quality improvement. The
underinvestment in quality-improvement
research can be compensated for by a
concerted, collaborative effort between
international and national research
programs. The author uses the "consumer
goods characteristics model" developed by
Ladd and Suvannunt to estimate implicit
prices of specific rice qualities. Rice markets
in three countries, Thailand, Indonesia, and
the Philippines, are studied to quantify
regional estimates of returns to research.
Unnevehr concludes that the demand for
milling quality is relatively constant
between countries, whereas the demand for
chemical characteristics can vary
dramatically.


von Braun, J., and P.J.R. Webb. 1989.
The impact of new crop technology on the
agricultural division of labor in a West
African setting. Economic Development and
Cultural Change 37(3): 513-34.
Von Braun and Webb analyze the effect of a
centralized-pump irrigation system for
1,500 hectares in central Gambia on gender
roles in agriculture. With the
implementation of this new technology in
1983, rice, once a "woman's crop," became
primarily a "male-controlled crop." This
shift principally occurred because as rice
yields increase, rice is no longer grown on
individual plots by women, but rather on
communal lands under the control of men.











It is this division of labor-between
individual and communal plots-and
technological change that affect gender
roles in rice production.


Walker, T.S. 1989. High-yielding varieties
and variability in sorghum and pearl millet
production in India. In J.R. Anderson and
P.B.R. Hazell (eds.), Variability in Grain
Yields: Implications for Agricultural Research
and Policy in Developing Countries.
Baltimore: Johns Hopkins.
Sources of production variability have
become critical areas of study as researchers
try to ascertain why variability around the
world has been rising. Walker uses data
from 48 sorghum and 40 pearl millet
producing regions in India for two 12-year
periods, one before the Green Revolution
and one after the Green Revolution, to
determine factors contributing to
production variability. Initially, it is
explained that the vast majority of
variability is derived from the covariance
between regions. Walker uses a weighted
least squares regression to determine the
effects of high-yielding variety adoption,
irrigated area, and variation in rainfall
covariance over the two time periods.
Higher adoption of both sorghum and pearl
millet has increased yield covariance
between regions, a higher rainfall
covariance has contributed to higher
production covariance, and irrigation
changes have contributed to higher
covariance for sorghum and lower yield
covariance for pearl millet.


Walker, T.S., and C.C. Crissman. 1996.
Case Studies of the Economic Impact of
CIP-Related Technologies. Lima, Peru:
International Potato Center (CIP).
Recent emphasis has been placed on
demonstrating practical applications of new
technologies. This collection of nine case


studies describes the impact of research
from the International Potato Center (CIP).
Walker and Crissman have put together a
collection of three case studies on varietal,
integrated pest management (IPM), and
seed system technology. The studies present
cost-benefit analyses of adoption in Eastern
and Central Africa, China, Peru, Tunisia, the
Dominican Republic, Vietnam, and India.
Topics include CIP-24 and CanchAn-INIAA
varieties, potato tuber moth, sweetpotato
weevil, and the Andean potato weevil in
IPM research, and various seed projects.


Winkelmann, D. 1976. The Adoption of
New Maize Technology in Plan Puebla,
Mexico. Mexico, D.F.: International Maize
and Wheat Improvement Center (CIMMYT).
This study describes the results of a plan to
develop, test, and disseminate
recommendations to increase maize yields
in Mexico. Winkelmann discusses the
objectives and organization of the initiative,
as well as factors limiting adoption of the
recommendations. In general, the
recommendation of increased nitrogen,
phosphorus, and planting density
dramatically increased yields in the test
area. The point of contention, though, was
the different ways of measuring adoption
rates. Even though adoption of the entire
recommendation may be relatively low, the
percentage of farmers who implemented
components of the new technology is much
higher. Winkelmann emphasizes that small-
scale farmers will modify their farming
practices in anticipation of higher profits,
but only to the extent to which they can
bear the additional risk. Since implementing
the entire recommendation requires
numerous increases in inputs, to reduce
risks many farmers settle for using a level of
inputs intermediate between their original
method and the recommendation. The
author explains that the rate of return to
investment in "intermediate" input research
will be higher than intensive input research.











Thus collaborative efforts of research and
extension institutions in making and
disseminating recommendations have been
much more beneficial for farmers than
estimates of the adoption of the entire
recommendation would illustrate.


Witcombe, J.R. 1989. Variability in the
yield of pearl millet varieties and hybrids in
India and Pakistan. In J.R. Anderson and
P.B.R. Hazell (eds.), Variability in Grain
Yields: Implications for Agricultural Research
and Policy in Developing Countries.
Baltimore: Johns Hopkins.
Witcombe uses data on varieties and
hybrids in India and Pakistan from the
International Crops Research Institute for
the Semi-Arid Tropics (ICRISAT) to
determine the comparative stability and
yields of varieties and hybrids. Individual


data are compared with population
aggregates for low-, average-, and high-
yielding environments through a regression
analysis. It is determined that hybrids have
higher yields, but varieties are more stable.
Mean variance and stochastic dominance
analyses are conducted to determine the
tradeoff between stability and variance in
choosing suitable varieties or hybrids. Mean
variance analysis revealed that for all
environments studied the variety or hybrid
to be chosen was the highest yielding of the
options. The stochastic dominance method
showed hybrids to be better than varieties
for low-yielding environments and over
most yield values.










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