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AN EVALUATION OF FACTORS INFLUENCING AWAY-FROM-HOME
CONSUMPTION OF CRAWFISH IN THE GULF REGION
A THESIS PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
UNIVERSITY OF FLORIDA
To Miao, our kid, and my parents
I would like to deeply thank Dr. Lisa House, chair of my supervisory committee,
for her advice and timeless help on this thesis. Also, I would like to thank Dr. Richard
Kilmer for giving me the chance to do research with him during my master's program.
Those experiences have broadened my view and enriched my knowledge base. Dr. House
and Dr. Kilmer have given me the most help and advice during my master's program, and
I would like to express my appreciation again to them.
I also want to thank the Food and Resource Economics Department for those who
have given me support and encouragement, like Dr. Robert (Jeff) Burkhardt, Dr. Donna
Lee, and Dr. Allen Wysocki, and particularly Jessica Herman, our program assistant.
Finally, my deepest gratitude goes to Miao and my parents for their support
throughout these years.
TABLE OF CONTENTS
ACKNOW LEDGM ENTS ........................................ iv
LIST OF TABLES ............. ........ ............. ........... ........ vii
LIST OF FIGURES .......... ............................. viii
ABSTRACT.................................. .............. ix
1 INTRODUCTION ................... .................. .............. .... ......... .......
Pream ble .................................................... ...............
Problematic Situation................ ...... ...............
Researchable Problem .............................................. ..... .. .7
Obj ectives ................... ...................................... ............... ......... 8
H ypotheses................................................................ 9
2 L IT E R A TU R E R E V IE W ...................................................................................... 11
3 SURVEY IN STRUM EN T................................................................................. .. ......17
Survey Instrument.......................... ...............17
Survey Contents................................ ....... .........19
4 D A T A ....................................................... 22
5 THEORETICAL MODEL AND MODEL SPECIFICATION............... ...............30
T h eoretical M odel ................... .................................... ...........................30
M odel Specification....................... ............... .. .............33
Truncated-at-Zero Count Data Double Hurdle Model ........................................38
6 EM PIRICAL RESULTS ................................................ ............... 40
Issues of Craw fish Consum ption .......................................................................... ........40
R regional Consum ption ................................................ ............... 40
Farm-Raised Crawfish............................. ......... ......... 40
D om estic Versus Im ported Crawfish ...................................... ........... ....41
Product Form ............................... .................. ....... 42
Reasons for Consuming and Not-Consuming ...................................44
R seasons for consum ing ........................................ ................. 44
Reasons for not consuming .............................. ............... 44
Away-From-Home Crawfish Consumption ........................................47
7 CONCLUSIONS AND IMPLICATIONS ..........................................62
Sum m ary ............... ....... .. .. ......... .. .. ........................ 62
APPENDIX 2004 MARKET SURVEY OF FOOD CONSUMPTION..........................71
L IST O F R E F E R E N C E S ............................................................................................. 76
BIOGRAPHICAL SKETCH .................................................. ............... 80
LIST OF TABLES
4-1. Residence region of survey respondents. .............................................. .....23
4-2. Summary of demographic information.............................. ...............27
4-2. Continued......................................... ......... 28
4-3. Descriptive statistics on other factors included in the Double-Hurdle model............29
6-1. Sample frequency distribution of the dependent variable (n=733). ........................48
6-2. Description of variables included in the double-hurdle model............... ...............50
6-2. Continued......................................... ......... 51
6-3. Empirical results of single-decision and double-hurdle: maximum-likelihood
estim ates and m arginal effects. ......................................................... 53
6 -3 C ontinu ed................ ........................................................................ .................. ...... 54
LIST OF FIGURES
1-1. United States per capital total, fresh & frozen fish and shellfish consumption............2
1-2. Percentage of away-from-home food expenditure at 1988 prices................................3
1-3. Percentages of seafood meals eaten away-from-home..............................................4
4-1. Comparison of U.S. population in the Southeast and survey respondents by age. ....26
4-2. Comparison of incomes of all the U.S. population and incomes of the survey
respondents...................................... ............................... ......... 26
6-1. Regional percentage of crawfish consumption........................ ............... 41
6-2. Comparison of preferences over domestic and imported crawfish products..............42
6-3. Categories of reasons given for consuming crawfish (crawfish consumers vs. away-
from -hom e consum ers). .............................................................. 45
6-4. Categories of reasons given for consuming crawfish (away-from-home consumers
only, at-home consumers only, and all crawfish consumers). ..............................45
6-5. Categories of reasons given for not consuming or not consuming more crawfish
(consum ers vs. non-consumers). ................................ ............... 46
6-6. Categories of reasons given for not consuming or not consuming more crawfish
(away-from-home only, at-home only, and non crawfish consumers). ................48
A-1. Crawfish pictures. ............................................... ........ 71
Abstract of Thesis Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Master of Science
AN EVALUATION OF FACTORS INFLUENCING AWAY-FROM-HOME
CONSUMPTION OF CRAWFISH IN THE GULF REGION
Chair: Lisa A. House
Major Department: Food and Resource Economics
U.S. consumers are traditionally known as away-from-home consumers of seafood
products. Over the past 20 years, consumption of ethnic foods has steadily increased. For
example, approximately 25 percent of Americans say they enjoy Cajun cooking. In the
United States, consumption of crawfish is usually associated with special events or Cajun
cooking, which differs from consumption of crawfish in other countries. Growth in
consumption has provided opportunities as well as challenges to Chinese exporters and
U.S. importers as well as domestic farmers, processors, and marketers of crawfish.
This thesis focuses on developing an understanding of factors influencing away-
from-home consumption of crawfish in the Gulf region. A web-based consumer survey
was conducted to obtain information about consumer preferences. Demographics as well
as stated consumer preferences have significant effects on both participation and
consumption decisions, but in different scales or directions. For example, enjoying the
flavor, preferring Cajun cooking, and adding variety in the diet were the main reasons for
consuming crawfish. The results also indicated that crawfish is an inferior good and
relatively price sensitive. Caucasians tend to be less likely to consume crawfish away-
from-home and to consume less frequently. Additionally, the lowest income group has
the highest likelihood and frequency of crawfish consumption.
Crawfish belongs to the scientific class Crustaceans. Crawfish has a hard external
shell, which provides protection to its body. These small crustaceans are related to
lobsters and closely resemble them. The Red Swamp Crawfish (Procambarus clarkia) is
the species that is the most acceptable for cooking, and is commercially produced and
consumed. The shell of the adult Red Swamp Crawfish is dark red to nearly black
(Ladewig and Schaer, 1993).
In the Southeastern United States and the Gulf region, particularly in Louisiana,
crawfish farming and consumption have been a part of the culture (Avery and Lorio,
1999). Catches from the wild are usually seasonal and unpredictable. Increases in product
demand beyond the amount traditionally caught in the wild led to crawfish farming
(D'Abramo et al., 2002). In the United States, consumption of crawfish is usually
associated with special events or Cajun cooking, which differs from consumption of
crawfish in other countries. This thesis will focus on developing an understanding of
factors that influence consumption of crawfish in the Gulf region.
Seafood includes aquaculture products such as crawfish and harvests from salt and
fresh water sources. In the United States, the consumption of seafood has become an
important part of the diet. According to the United States Department of Agriculture
(USDA), the consumption of seafood has increased in recent decades. The estimated per
capital seafood consumption increased by three pounds from 1970 to 1992, to 14.7 pounds,
and it increased further in the 1990s. In 2000, the estimated per capital consumption of
seafood was 15.6 pounds (Figure 1-1).
Total Fresh & Frozen
Source: USDA-ERS, 2002a.
Figure 1-1. United States per capital total, fresh & frozen fish and shellfish consumption.
Nearly two-thirds of the consumption of seafood was in the form of fresh and
frozen products, the remainder was in processed products such as canned and cured. This
compares to 57- 60 percent in the 1970s (Figure 1-1). In value terms, according to the
National Fisheries Institute (NFI), American consumers spend almost $50 billion each
year on a wide variety of fish and shellfish products. The thousands of firms that produce,
process and distribute fish and shellfish are located throughout the United States, and
annually contribute more than $25 billion to the U.S. gross national product (NFI, 2003).
Along with eating more seafood, U.S. consumers are dining out more often than
ever before (USDA-ERS, 1999a). Away-from-home food expenditures increased from 36
percent of total food expenditures in 1970 to 47.5 percent in 1996, and 48 percent in 2001
(Figure 1-2). "Reasons for this trend include smaller household size, more affordable and
convenient fast food services, a growing number of women working outside the home,
and higher household incomes" (USDA-ERS, 1999a).
Source: USDA-ERS, 2002b; USDA-ERS, 2002c.
Figure 1-2. Percentage of away-from-home food expenditure at 1988 prices.
US consumers are traditionally known as away-from-home consumers of seafood
products. Although no precise data are available, one estimate by Keithly (1985)
suggested that the quantity of away-from-home consumption of seafood products ranged
from one-third to two-thirds of all seafood consumed. A recent study by Selassie, House,
and Sureshwaran (2002) found 57, 62, and 58 percent of meals of shrimp, oysters, and
catfish, respectively, were consumed away-from-home (Figure 1-3). This set of figures
compares to general food consumption, where 16 percent of the meals were eaten away-
from-home in 1978, a figure that increased to 29 percent by 1995 (USDA-ERS, 1999a).
Crawfish can be seen as a healthy food, which is "high in minerals and protein, and
low in calories and saturated fat" (Ladewig and Schaer, 1993). Also, according to the
Florida Department of Agriculture and Consumer Services (FDACS), crawfish is known
for its delicious meat, and is consumed all over the United States (FDACS, 1992).
Meals* Shrimp Oyster Catfish Seafood
Note: All meals data were from 1995, other categories were from 2001 (more recent data not
available for all meals).
Source: Selassie, House, and Sureshwaran, 2002; USDA-ERS, 1999a.
Figure 1-3. Percentages of seafood meals eaten away-from-home.
When talking about the consumption of crawfish, people used terms such as
"Louisiana parties, family gatherings, and Cajun-style boiled crawfish" (Ladewig and
Schaer, 1993). Traditionally, most crawfish in the United States was consumed in
Louisiana (Dellenbarger et al., 1996). Over the past 20 years, consumption of ethnic
foods in the United States has steadily increased, with approximately 25 percent of
Americans indicating they enjoy Cajun cooking (RoperASW, 2002). Particularly, a large
proportion of young consumers indicate a preference for ethnic foods (FMI, 2003). Since
younger consumers are usually seen to set future trends, their preference of ethnic foods,
including Cajun-cooking might hint at an increasing demand for crawfish. As a result, the
demand for Cajun dishes that include crawfish is steadily growing, and the potential for
growth in the crawfish industry is high.
Due to the increases in year-round demand for crawfish and the seasonality and
unpredictability of crawfish caught from the wild, crawfish aquaculture has arisen. "The
majority of crawfish produced in the United States is used for food and originates in
Louisiana" (McCullough et al., 2001), and the price generally is considered expensive,
particularly in other regions. An increased interest in finding alternative sources of
income has led "farmers to transform their fields into crawfish farms, and has expanded
production along the Gulf coastal regions of the United States" in the last 30 years
(Ladewig and Schaer, 1993).
A suitable crawfish pond needs relatively flat land, soil with a high clay content,
and an adequate water source. The states in the Southeast and Gulf region have
geographic and climatic advantages in crawfish production (FDACS, 1992). Nevertheless,
although the growing demand for crawfish has heightened the interest of agricultural
producers, the industry in states other than Louisiana is still comparatively weak. For
example, due to the state regulations on crawfish aquaculture in Florida, there were only
21 facilities certified as crawfish producers in the year of 2003. Among those 21 farms,
less than 15 farmers produce crawfish for the food market, and the acreage for crawfish
producing is relatively small (FDACS, 2003).
In 1990, there were about 160,000 acres of managed crawfish ponds in the United
States, and total harvest of crawfish was around 760 million pounds a year (Ladewig and
Schaer, 1993). However, due to the rapid increase of imports since 1994, crawfish
production decreased to about 36 million pounds in 1998 (USDA-ERS, 1999b). In the
year 2000, total harvest of crawfish in the US was around 100 million pounds (FDACS,
2001), partly as a result of tariffs on imported crawfish. Crawfish production is mainly in
the lower Gulf Coast regions, such as Texas, Mississippi, Florida, and Louisiana, with
most of the acreage found in Louisiana (Avery and Lorio, 1999).
It is worth mentioning that since 1994, an increasing proportion of the market
volume has been imported from foreign countries such as China and Spain. The market
share of imported crawfish increased to 87 percent in 1996 (Roberts, 2000), and imports
continuously increased 173 percent in 1998. The total quantity was over six million
pounds in 1998, mainly in the form of tail meat (McCullough et al., 2001). The
International Trade Commission (ITC, 1997) has found that the increasing crawfish tail
meat imports from China have caused material injury to the domestic crawfish processing
industry, and has imposed Less Than Fair Value (LTFV) duties on crawfish since 2000
(Roberts, 2000). The average import tariff is as high as 123 percent, and there also are
levies on past shipments. Over 90 percent of crawfish imports come from China even
with restrictive duties (McCullough et al., 2001). Because of the limited quantities of
crawfish available in the U.S. market, prices have been higher in recent years. Given the
deficit in domestic supply, it appears there will be opportunities for crawfish farming in
Although consumption data for crawfish are not available, according to several
studies on crawfish consumption (Ladewig and Schaer, 1993; Yen et al., 1995,
Dellenbarger et al., 1996; McCullough et al., 2001), the demand for crawfish has
increased, and the growth in consumption has provided both opportunities and challenges
to Chinese exporters and US importers as well as domestic farmers, processors, and
marketers of crawfish. However, domestic market feasibility, market growth potential,
and market size and trends are still unknown, and there are concerns about the viability of
crawfish production and marketing.
Knowledge about consumers' preferences and perceptions in terms of crawfish
consumption becomes important in identifying the viability of crawfish production and
marketing. The lack of information about consumer preferences is a serious barrier to
answering questions about the viability of crawfish production and marketing. Therefore,
for the growth of the industry, especially in the Gulf region, new information is needed
on the factors that influence crawfish consumption patterns.
For crawfish, factors that might influence the consumption decision and frequency
of consumption are unknown. Further, it is not known if these factors have the same
influence on at-home consumption as compared to away-from-home consumption
decisions. Developing an understanding of those factors that influence consumption of
crawfish becomes comparatively important.
Growth in consumption has offered opportunities and challenges to producers,
processors, and marketers of crawfish. Knowledge about consumers' preferences and
perceptions in terms of crawfish consumption is important for identifying the viability of
crawfish production and marketing. While potential producers and importers of crawfish
may question the profitability of new crawfish ventures, processors, and marketers may
question the viability and profitability of crawfish marketing. The lack of information
about consumers' preferences and perceptions is a serious barrier to assessing the
viability of crawfish production and marketing. Therefore, new information is needed
about factors, such as demographic, socioeconomic, and consumers' preferences and
perceptions about crawfish, which might influence the probability and the frequency of
Due to the fact that Americans are traditionally away-from-home seafood
consumers and most crawfish are consumed in the Southeastern United States, and away-
from-home consumption is the main means of introducing seafood to new consumers,
this study will focus on developing an understanding of factors that might influence
away-from-home consumption of crawfish in the Southeastern United States, particularly
in the Gulf region.
The overall objective of this study is to develop an understanding of the factors that
influence away-from-home consumption of crawfish. We will collect information from
existing and potential crawfish consumers in the Gulf region, and study the effects of
geographical regions and household characteristics for away-from-home crawfish
consumption that are not available in aggregate time series. Also, stated consumer
preferences and perceptions regarding taste, flavor, nutrition, safety, appearance, and
availability will be examined to see whether they affect the consumption decision and
consumption frequency. Specific objectives are:
* To inform producers, processors, and marketers about what attributes of crawfish,
such as taste, flavor, nutrition, safety, and appearance, and which form of crawfish
product (whole boiled or tail meat) are preferred by current and potential
consumers in the Gulf region.
* To inform importers of crawfish about the factors that will influence the demand
and market trends of crawfish in the near future.
* Due to the domestic popularity of crawfish in China, Chinese exporters target the
United States as one of the biggest importing countries of crawfish. Information
about factors that influence consumption might help Chinese exporters better
understand the different preferences and perceptions regarding crawfish.
Patterns of away-from-home consumption are likely to differ from at-home
consumption. Moreover, for crawfish, it is likely to differ from other seafood
consumption and differ from consumption in other countries. Many factors might
influence participation and consumption decisions. Those factors can be separated as
demographics and preferences or perceptions. Demographics might include geographical
regions, ethnicity, household income, and educational levels. In addition to price,
consumer perception regarding taste, flavor, nutrition, safety, appearance, and availability
might influence crawfish consumption. Given these considerations, the following
hypotheses are proposed:
* Crawfish consumption will vary by region of residence. Consumers from the main
production regions will be more likely to consume crawfish.
* Farm raised and/or domestically produced crawfish will be preferred by consumers
over wild caught and/or imported crawfish.
* Fresh crawfish and tail meat will be preferred by consumers in accordance with the
market trends toward convenience and freshness.
* Education and household income will negatively affect the probability of away-
from-home crawfish consumption.
* Household size, education, and household income will positively affect the
frequency of away-from-home consumption among households that do consume
* Other demographics, such as age, race, and ethnicity will influence both the
probability and frequency of away-from-home crawfish consumption. For example,
older groups will be more likely to consume crawfish. On the contrary, Caucasians
are less likely to consume crawfish and consume it less frequently.
* Consumer preferences, including taste, nutrition, and availability issues, will affect
the participation decision for away-from-home crawfish consumption.
* Consumer preferences, including taste, nutrition, and availability issues, will affect
the frequency of away-from-home crawfish consumption.
* Consumer perceptions regarding seafood safety and appearance will negatively
affect participation and consumption decisions.
Not many empirical studies focusing on crawfish consumption patterns exist in the
literature. Few studies have focused on crawfish consumption, and no study has
examined away-from-home consumption of crawfish in the Gulf region. Studies on
crawfish consumption patterns were mostly conducted in the early to middle 1990s. As a
result, new information is needed.
Two previous studies, Yen et al. (1995) and Dellenbarger et al. (1996), examined
crawfish consumption in South Louisiana and Louisiana, respectively. Yen et al. (1995)
investigated the determinants of crawfish consumption in South Louisiana using a
generalized limited dependent variable model that is similar to Cragg's double hurdle
model (Cragg, 1971).
The study included socio-economics and demographics as the independent
variables, and no price or expenditure data were collected. The independent variables
included income, household size, and dummy variables indicating professional types,
employment status, education, religion, and race. The quantities (in pounds) of crawfish
consumed by the responding households during a five-day period previous to the survey
were collected as the dependent variable. It is worth mentioning here, among its 915
responding households, only 200 households, or 21.9 percent, reported consumption of
The study found that demographics, such as income, household size, and skilled
labor, increased the likelihood of crawfish consumption but not the conditional level of
consumption. For example, households characterized by the attributes of higher income,
larger household size, skilled labor, Catholic, and white are more likely to consume
crawfish than others. In terms of the conditional level of crawfish consumption, they
found that education and employment status are among the household characteristics that
determine the level of consumption. Households with skilled laborers or unemployed
workers consume more crawfish than other groups. In addition, the results suggest that
consumption of crawfish is income inelastic, although insignificant.
However, the study only centered attention on the most recent five-day period of
crawfish consumption, and thus ignored the seasonality of the crawfish harvest.
Moreover, the study only included socio-economics and demographics that might
influence consumption; however, it did not illustrate other factors regarding consumer
preferences and perceptions, which might also influence crawfish consumption.
A shortcoming of the study is the method in which the dependant variable was
obtained. Respondents were asked to recall how many pounds of crawfish they had
consumed in the five-day period. Respondents were then converted to live-product
equivalents. The calculation of the dependent variable caused discrepancies from realistic
quantities. However, it is not unexpected as respondents may find it hard to estimate the
quantity consumed in pounds.
Dellenbarger et al. (1996) examined the consumption of boiled crawfish in
Louisiana by using a mail survey. A Logit model was used to estimate the probability of
household consumption of boiled crawfish. The study surveyed "four rural and four
urban parishes of Louisiana to identify their crawfish and seafood consumption patterns".
As a result of the small survey region, interpretation of the study should be conducted
Of 858 effective observations, 203 households, or 23.6 percent, reported
consumption. The study only focused on participation decision, and households were
asked if they had consumed boiled crawfish in the last five days. As a result, a Logit
analysis was used. A value of one represented households consuming boiled crawfish,
and a value of zero represented non-consumption. The dependent variables included
income, household size, urban resident, race, religion, and education.
The study found that religion had an influence on the probability of crawfish
consumption. Catholic and Protestant respondents were more likely to consume crawfish.
Also, white households were more likely to consume boiled crawfish than non-white
households. However, unlike Yen et al.'s findings, education was not a statistically
significant variable in determining the likelihood of boiled crawfish consumption.
The study suggested "households with incomes below $25,000 should be targeted
for boiled crawfish consumption, since crawfish consumption declined with income".
Additionally, the results showed that urban households had a lower probability of boiled
crawfish consumption compared to rural households.
Schupp et al. (1991) studied U.S. food stores' handling of crawfish, finding that
"many consumers were not knowledgeable about aquaculture products, especially in
areas of limited or no local production" (Schupp et al., 1991). In addition, market
expansion for crawfish outside the South Central region was found to be largely
dependent on obtaining the support of grocery stores. The study found that many
existing markets for crawfish are not being met by the current domestic supply and many
people do not know how to prepare crawfish at home. Availability is limited and crawfish
is likely not to be found in local supermarkets.
Other empirical studies focusing on seafood consumption patterns include Keithly
(1985), Cheng and Capps (1988), Yen and Huang (1996), and Drammeh et al. (2002).
Keithly (1985), using food consumption survey data, focused on a set of socio-
economic and demographic factors that affect at-home consumption of total seafood and
five specific products. He found that region, urbanization, race, household size, money
value of meals consumed away-from-home, and income were all contributing factors that
helped to explain at-home seafood consumption patterns.
Cheng and Capps (1988) investigated the key socio-demographic determinants of
at-home demand for several fresh and frozen finfish and shellfish species. They found
factors explaining the variation of expenditures on seafood were own price, household
income, household size, coupon value, geographic region, urbanization, race, and
Drammeh et al. (2003) found source of seafood for consumption, enjoyment of
flavor, availability, price, allergies, gender, and geographic reasons to be significant in
determining probability of participation in oyster consumption. They found the double-
hurdle model was a significantly better fit than the tobit model. Variables significant in
the level of consumption of oysters included source of seafood for consumption,
enjoyment of flavor, tradition, price, product safety, geographic region, income, and age.
Yen and Huang (1996) performed a detailed study on household demand for finfish.
The study estimated household demand for finfish in the United States using a limited
dependent variable model similar to Cragg's double hurdle model, which accounted for
both participation and consumption decisions.
The study found that the price of finfish, shopping frequency, geographic region,
race, and life-cycle variable were the key factors that significantly affect both the
probability of participation and the level of household finfish consumption in the United
States. Furthermore, they found "a variable might exert opposite effects on the
probability and level of seafood consumption".
Also, the study concluded that the double hurdle model was particularly relevant
for studying seafood consumption behavior, because the participation and consumption
decision were likely to differ. Results of the analysis were useful for seafood marketers in
planning and developing marketing strategies. Based upon the results, seafood marketers
can differentiate between the factors that influence participation decisions and the factors
that influence consumption decisions.
In conclusion, there have not been many empirical studies of crawfish consumption
in the Southeast and the Gulf region, particularly in recent years. As a result, research
conducted to study the consumption of crawfish, including regions beyond Louisiana,
would be useful. In addition to demographics, factors regarding consumer preferences
also influence the consumption of crawfish either at-home or away-from-home. It has
been suggested to include those factors in the analysis of crawfish consumption patterns.
Those factors include information from current and potential crawfish consumers about
their preferences and perceptions of crawfish to determine which of these might influence
decisions and the frequency of crawfish consumption. Attention to the consumption
patterns and the identification of those factors could be helpful in developing marketing
strategies for the industry targeting these markets.
This study will examine away-from-home consumption of crawfish in the lower
Gulf regions using data collected from an Internet-based survey. The web-based survey
was conducted in late January of 2004, which was just before the main crawfish harvest
season. However, the survey asked the frequency of away-from-home crawfish
consumption in the previous 12-month period to accommodate the seasonality of
crawfish consumption. Although it is expected that recalling the frequency of
consumption over 12 months may be difficult, in the case of crawfish the low overall
level of consumption during one year reduces this concern. For example, people can
remember one time without difficulty, but cannot easily remember 100 times.
Web-based surveys are increasing in popularity with the growth of the Internet.
Some advantages of a web-based survey include "the ability to use color graphics, higher
response rate and higher completion rate, and lower cost compared to other survey
instruments" (Larkin et al., 2002).
Color graphics can be very expensive for mail surveys and impossible for
telephone surveys. In our food market survey for crawfish consumption, color graphics
were included to illustrate crawfish, following a verbal description. Since crawfish
resemble lobster, it is extremely important to avoid confusion by providing color graphics.
Participants were recruited through Survey Sampling, Inc.'s web-survey service.
Similar to telephone survey centers, this service charged per completed survey, thus
allowing the researcher to guarantee the number of responses. This differs from mail
surveys where the response rate is highly dependent on factors like survey length. By
surveying on the Internet, respondents might be more likely to complete the entire survey.
Additionally, in each question page, blank responses can be disallowed in some critical
questions by using reminder dialogue boxes.
Compared to mail surveys and focus groups, the web-based survey lowers the cost
and increases the completion rate. With the growth of the Internet and Information
technology, the web-based survey is one of the most effective survey instruments.
However, there are still some disadvantages of conducting a web-based survey such as
"non-representation of consumers without Internet access" (Larkin et al., 2002).
Uncompleted surveys still exist. Also, if a respondent completes the survey several times,
it would be difficult to pick only one as the final response. Steps can be taken to address
Another important issue included in the web-based survey instrument is how to
obtain potential respondents. Our method involved contracting a survey sampling
company, which can provide the stratified survey sample with the potential respondents
fitting our specific requests such as region of residence, demographic compositions
comparable to the Census data, etc. An additional advantage of using an Internet survey
service is that participants have agreed to participate in web surveys, leading to a higher
The procedures of how respondents completed the Internet survey are shown below:
Once the respondents had read the welcome page and started the survey, a time stamp
1 See Larkin et al. (2001) for details of developing an Internet survey instrument.
would automatically record when the respondent started the survey. Responses were
'submitted' when the respondent completed one page and wanted to move to the next web
page. To receive the data in different stages, the survey questions were organized into a
series of five pages. The resulting files for each page were retrieved only by the survey
authors, not by the survey sampling company.
The purpose of the web-based survey is to collect information about crawfish
consumption patterns. Once the respondents began the survey, responses were submitted
when the respondent completed each page of the five-page survey. Interruption during
completion had smaller impacts on completion rate than an Internet survey with only one
long page. For example, a survey was not considered completed for the survey sampling
company until all five pages were completed. However, we obtained data from
respondents who completed less than all five pages of the survey. The designing of
survey questions was the critical part for the success of the web-based survey. Our web-
based survey can be accessed at http://www.agsurveys.org/food, and the contents are
included in the Appendix.
After the respondents read the welcome page and gave their informed consent, they
were asked to click the 'start' button to begin the survey if they were the member of the
household that usually decides what food to purchase. As we mentioned before, a time
and date stamp recorded the beginning time to monitor how long the respondents took to
complete the survey. Basic information, including the description, scientific names, and
color graphics of crawfish, was provided on the second page. The first two questions
asked respondents whether they could distinguish between crawfish, lobster, and
langostino. Because crawfish are related to lobsters and closely resemble to them, it is
believed that respondents might not perceive the difference. One reason to ask these
questions was that we wanted to understand how knowledgeable people were about
crawfish. Another reason was we wanted to make sure that, after reading the description,
respondents could tell that, although related, crawfish are different from lobster and
langostino, and to ascertain whether they were answering the survey for crawfish and not
The following two questions asked the respondent if they had ever eaten crawfish
and, if so, if they had eaten crawfish in the last 12 months. A simple redirect was used to
lead respondents who had not eaten crawfish in the last 12 months to the final page, while
others proceeded to answer questions about crawfish consumption.
The dependent variable in this study is the frequency of away-from-home
consumption of crawfish. For each respondent who had consumed crawfish, we first
questioned them on how many times they had eaten crawfish in the last 12 months. To
obtain the dependent variable for this study, we then questioned them on how many times
they had eaten crawfish both at-home and away-from-home in the last 12 months. For
the crawfish consumers, questions were designed to obtain respondents' perceptions and
preferences on attributes such as farm-raised vs. wild caught crawfish and domestic vs.
imported crawfish, respectively.
Preferences on attributes regarding product forms were also obtained for away-
from-home and at-home consumption. Main product forms of crawfish in this study
include whole-boiled crawfish and crawfish tail meat, which are the dominant forms in
the existing market. Whole-live crawfish were not covered because we were only
concerned about away-from-home consumption and people seemed unknowledgeable
about cooking crawfish at home according to our pre-survey study. Other attributes
included frozen and fresh crawfish.
In order to obtain price preferences on crawfish, we asked questions about how
much they would pay for one pound whole-boiled crawfish and one pound crawfish tail.
Typical prices were obtained through a pre-survey study, mainly from the local market
and the web-based crawfish trader. Typical prices included whole-boiled crawfish
(medium, three to five dollars per pound, and large, six to seven dollars per pound) and
tail meat, 10 to 14 dollars per pound. The preferences on price might give insight on how
much consumers would be willing to pay for one pound whole-boiled crawfish and one
pound tail meat. Also, respondents were asked to select the top three reasons why they
did not eat crawfish, including price. Other variables for eating crawfish included
enjoyment of flavor and taste, enjoyment of texture, health and nutrition benefits,
tradition and habit, prices or cost, availability, variety in diet, and prefer Cajun style.
The final page of the survey (completed by both those who had consumed crawfish
in the last 12 months and those who had not) included a question asking respondents to
identify the top three reasons why crawfish was not eaten, or was not eaten more
frequently. Variables for the top three reasons included prices, do not like the product
form, no custom, do not like texture and taste, do not like the smell, no local farm-raised
available, safety concerns, bad impression, health reasons (allergy), and vegetarian.
The final part of the survey included socio-economic and demographic questions
such as household income, household size, employment status, marital status, religions,
and race. The information became extremely important in analysis of away-from-home
consumption of crawfish, based on previous empirical studies.
The data for this study were obtained through a web-based consumer survey.
Targeting the Gulf region, the web-based survey was conducted in late January of 2004.
Respondents were asked about the frequency of away-from-home crawfish consumption
during the previous 12 months. Recall bias for the crawfish consumption is minimized
because of the nature of the web-based survey. Crawfish consumption is expected to be
seasonal. We asked for a 12-month recall period to accommodate the seasonality of
crawfish consumption, given the low overall level of crawfish consumption in one year.
Survey Sampling, Inc. provided a stratified survey sample for the survey. The
chosen stratified sample was confined to the Southeast and the Gulf region. Different
census regions were expected to be a significant determinant of both the participation and
consumption decision on away-from-home consumption of crawfish. The survey was
published on the website (agsurveys.org/food) in late January of 2004, with a total of 765
responses to the questions related to crawfish consumption. As mentioned before,
compared to the mail survey instrument, the web-based survey is more effective and
efficient in data collecting. Although the response rate for our survey was about 14.1
percent, we have a very high completion rate, 90 percent, which means, once the
respondents started the survey, 90 percent would finish it. In this study, we used 733
effective records, which provided full information on crawfish consumption for this study.
Cases with incomplete socio-economic and demographic information, such as income
and gender, were dropped from the sample. In addition, responses with uncompleted
answers and irrational answers were eliminated as well. The information obtained from
these 733 responses is summarized below.
We considered three census regions. For comparison, we divided the large
Southeast Atlantic region into Northern and Southern areas (Table 4-1). The demographic
data collected in this study indicated that the response rate per region in the Gulf region
was relatively comparable, ranging from 129 effective responses from the East South
Central region to 208 responses from the Southern Southeast Atlantic region (Table 4-1).
The comparison to the percentage of population in these regions is included in the table.
Table 4-1. Residence region of survey respondents.
% of the
Region of Number of % of Survey
S States Included in Region Population in
Residence Responses Responses r
Northern Delaware, Washington D.C., 190 26.0 28.1
Southeast Maryland, North Carolina,
Atlantic Virginia, West Virginia
Southern Florida, Georgia, South 208 28.4 23.5
East South Alabama, Kentucky, 129 17.6 17.0
Central Mississippi, Tennessee,
West South Arkansas, Louisiana, 206 28.1 31.4
Central Oklahoma, Texas
Compared with U.S. Census data (US Census Bureau, 2000), the responses did
appear biased towards Caucasians. A large percentage of the respondents in the survey,
88.2 percent, indicated they were Caucasian, followed by 8.0 percent Black or African-
American, 1.5 percent Asian, 2.3 percent Indian, and 3.7percent other. These compare to
the 2000 U.S. Census data, with approximately 75 percent of the U.S. population
Caucasian, 12.3 percent Black or African-American, and 4.2 percent Asian. The results
also indicated a bias towards non-Hispanic, with only 3.4 percent of the respondents
indicating they were Hispanic or Latino. This compares to the Census data, with 12.5
percent of Hispanic origin (U.S. Census Bureau, 2000). However, this is not uncommon
for survey responses on seafood consumption.
Figure 4-1 shows the percentage of U.S. population and survey respondents in
different age groups. Although discrepancies exist, survey respondents were somewhat
comparable to the population average, with 46.4 percent of the U.S. population over the
age of 45. Also, the survey respondents tended to have comparable household incomes to
those from the U.S. Census data (Figure 4-2). The median income of the survey
respondents fell in the $40,000 $59,999 category, compared to a U.S. median income of
$41,994. However, our survey respondents were more educated than average, with
approximately 40 percent of the sample having a four year college degree compared to 26
percent in the general population, according to the 2000 Census data. As a result,
interpretation of the results should be conducted recognizing the bias, and future studies
should make an attempt to focus on the underrepresented population (e.g. Hispanic
Overall, among the 733 responses, 58.4 percent (428 responses) indicated they had
consumed crawfish, 30.0 percent (220 responses) indicated they had consumed crawfish
in the last 12 months, and 25.8 percent (189 responses) indicated they had consumed
crawfish away-from-home during the last 12-month period. Only 11 percent (82
responses) indicated at-home consumption, and 4.2 percent (31 responses) indicated
consumed crawfish only at-home.
Tables 4-2 and 4-3 provide descriptive statistics for the survey, including the
respondents who had indicated crawfish consumption in the last 12-month period.
Respondents were asked to indicate the times they have consumed crawfish at-home and
away-from-home in the last 12 months. The frequency of away-from-home consumption
of crawfish is the sum of responses to the two questions about at-restaurant and at-other-
away-from-home consumption. Respondents who ate crawfish away-from-home
consumed crawfish, on average, 2.97 times (standard deviation 2.682) in the last 12-
Additionally, other factors included socio-economic and demographic variables
(age, ethnicity, household income, education, etc.), preferences for consuming or not
consuming, and knowledge about crawfish. Descriptive statistics for the survey sample
are shown in Tables 4-2 and 4-3.
18-24 25 to 34 35 to 44 45 to 54 55 &
Figure 4-1. Comparison of U.S. population in the Southeast and survey respondents by
$19,999 or $20,000 $40,000 $60,000 $80,000 or
less $39,999 $59,999 $79,999 greater
Figure 4-2. Comparison of incomes of all the U.S. population and incomes of the survey
Table 4-2. Summary of demographic information.
Non- Non-Away- Away-From- Overall
Consumers From-Home Home
Consumers a b Sample
_Consumers _Consumers Consumersb Sample
Number of Observations 513 220 544 189 733
Age of Respondents % % % % %
Greater than 55 19.9 19.4 19.9 19.5 19.7
Between 45 and 55 26.7 25.2 26.5 25.9 26.3
Between 35 and 45 23.2 27.9 24.3 25.9 24.7
Between 25 and 35 22.2 19.4 21.7 20.6 21.4
Between 18 and 25 8.0 8.1 7.2 7.9 7.7
Percent Female 82.7 69.5 82.2 68.8 78.7
Less than $19,999 15.4 11.7 15.1 12.2 14.3
Between $20,000 and 29.8 28.2 30.3 26.4 29.4
Between $40,000 and 25.3 20.0 25.0 20.1 23.7
Between $60,000 and 15.0 14.5 15.1 14.3 14.8
$80,000 or greater 14.4 25.4 14.5 27.0 17.8
Region of Residence
Northern Southeast 32.0 11.8 30.9 11.6 26.0
Southern Southeast 28.3 28.6 27.6 30.7 28.3
East South Central 18.1 16.4 18.8 14.3 17.6
West North Central 21.6 43.2 22.8 43.4 28.1
High School or less 45.8 37.3 46.0 35.4 43.2
Some College (2 Yr) 17.9 14.5 17.5 15.3 17.0
College Degree (4 Yr) 27.5 30.0 27.6 30.2 28.2
Above College 8.8 18.2 9.0 19.0 11.6
Number of Children (under 16 living at home)
No Children 61.8 57.7 60.8 59.8 60.6
1 or 2 Children 29.2 30.9 29.2 31.2 29.7
Above 3 Children 9.0 11.4 9.9 9.0 9.7
1 Only 15.0 9.5 14.5 10.0 13.4
2 People 36.3 35.9 35.7 37.6 36.1
3 People 21.4 18.6 20.8 20.1 20.6
4 People 15.0 21.0 15.6 20.1 16.8
5 and above 12.3 15.0 13.4 12.2 13.1
Table 4-2. Continued.
Race (races are alone and in combination)
White 88.9 87.3 89.3 85.7 88.4
Black 8.8 5.9 8.5 6.3 7.9
Asian 1.2 1.8 1.1 2.1 1.4
Indian 2.0 3.2 2.0 3.2 2.3
Other Race 2.5 6.4 2.4 7.4 3.7
Christian" 51.9 53.2 52.8 50.8 52.2
Catholic 12.7 11.4 12.3 12.2 12.3
Jewish 2.1 1.8 2.0 2.1 2.0
Other Religions 4.5 4.1 4.4 4.2 4.4
No Religion 28.9 29.5 28.5 30.7 29.1
Hispanic 2.9 4.5 2.9 4.8 3.4
a Non-Away-From-Home consumers included non-consumers and only at-home consumers.
b Away-From-Home consumers included only away-from-consumers and away-from-home
consumers who also were at-home consumers of crawfish.
Christian including Protestant.
Table 4-3. Descriptive statistics on other factors included in the Double-Hurdle model.
Mean, Non Away- Mean, Away- Overall
From-Home (544) From-Home (189) Mean (733)
Frequency of Consumption (times in the last 12 months):
Away-From-Home 0 2.97 (2.682)a 0.77 (1.882)
At-Home 0.18(1.32) 0.72 (1.611) 0.32 (1.423)
Knowledge of Crawfish % % %
Knowing the difference between 73.5 89.5 77.7
crawfish and lobster
Knowing the difference between 25.6 45.0 30.6
crawfish and langostino
Indicated the following was one of the top three reasons for consuming
Enjoy flavor 5.2 86.4 26.3
Health/Nutrition 0.9 14.1 4.4
Tradition/Habit 1.7 21.5 6.8
Price is attractive 1.1 14.1 4.5
Availability 1.3 23.6 7.1
Variety in diet 2.0 37.7 11.3
Prefer Cajun style 3.1 44.0 13.7
Indicated the following was one of the top three reasons for not consuming:
Price too high 24.8 58.2 33.3
No preferred product form 32.4 12.0 27.1
Not part of custom 20.8 20.0 20.5
Dislike taste 27.4 5.8 21.8
Dislike smell 31.1 16.9 27.5
Lack of domestically produced 26.5 22.0 25.3
Product safety concerns 9.6 20.1 12.3
Bad impression 31.4 12.6 26.5
Health concerns 6.1 5.8 6.0
a Standard deviations were reported in the parenthesis.
THEORETICAL MODEL AND MODEL SPECIFICATION
Neoclassical demand theory suggests own price, income, the prices of substitutes
and complements, socio-economic and demographic variables are determinants of
demand. Euler's theorem for homogeneous demand functions shows (Nicholson, 2002):
ex, Px + ex, Py +* + ex, P + ex, I 0
where e,P, is the own-price elasticity of demand, e,py and e,p and all cross-price
elasticities in-between are cross-price elasticities of demand with respect to all other
goods, and ex, is the income elasticity of demand. This property of the demand function
will give insight into crawfish consumption analysis, although we did not calculate those
elasticities in quantitative terms. In this study, the sensitivity of x (crawfish) to price (Px,
P,, P,) and income levels will be evaluated in general qualitative terms. However,
consumption of substitute products (such as other seafood) was not available. With
information about the sensitivity ofx (crawfish) to own-price and income levels, we can
infer a potential relationship between crawfish and its substitutes.
In this study of crawfish consumption patterns, the main forms of crawfish
consumed away-from-home are whole-boiled crawfish and tail meat. Different product
forms may have different prices, which are difficult to aggregate. Moreover, it is hard to
get aggregate prices because of the seasonality of the crawfish harvest and variety of
consumption locations (at-home vs. away-from-home). The main purpose of this study is
to develop an understanding of the factors influencing away-from-home consumption of
crawfish, not to derive the demand function for crawfish. As a result, we did not include
prices as a quantitative independent variable. However, in order to examine the impact
price has on away-from-home consumption of crawfish and to examine the own-price
elasticity in comparative terms, we include price as a binary variable. If respondents think
prices are the main reason for their participation and/or consumption decision, the value
of the variable would be one; otherwise, it would be zero.
This study will examine the factors influencing away-from-home consumption of
crawfish in the Gulf region using data from a web-based consumer survey conducted in
late January of 2004. The survey instrument was discussed in the previous chapter. The
frequency of crawfish consumed away-from-home in the last 12-month period is used as
the dependent variable. Respondents were asked to indicate how many times they
consumed crawfish away-from-home in the last 12 months. As mentioned before, the
reasons for a 12-month period includes seasonality of crawfish consumption and overall
low levels of consumption in one year. In this study, consumers, on average, ate crawfish
away-from-home three times during the last 12 months. If asking for one month, the
average times could be greater than, equal to or less than the annual average of three
The frequency of at-home consumption of crawfish is included to check the
relationship between at-home and away-from-home consumption and to infer if increases
in away-from-home consumption would occur at the expense of at-home consumption of
crawfish. Factors, including stated consumer preferences and perceptions regarding
crawfish, also are included as explanatory variables. For example, the survey includes
questions about the top three reasons for consuming or not consuming crawfish
(respondents were asked to select the top three reasons from a list, including prices,
availability, tradition, variety, flavor and taste, safety concerns, and health reasons).
Moreover, socio-economic and demographic data, such as age, education level, income,
gender, and ethnicity, will be examined to determine their impact on participation and
Censoring and truncation of the dependent variable is a very common problem in
survey data. In previous seafood consumption studies (Keithly, 1985; Lin and Milon,
1993; Yen and Huang, 1996; House et al, 2003), researchers found significant proportions
of households with zero observations. Conventional regression methods fail to account
for the qualitative difference between limit (zero) observations and non-limit (positive)
observations. Early studies with limited dependent variables used the Tobit model (Tobin,
1958). For example, Keithly (1985) used a Tobit model to accommodate the problem of
The Tobit model specifies that
P' xi +, N(0, a2)
y, = 0 ify, <0,
y, = y* ify,* >0
where y,* is the latent variable, and y, is the dependent variable. The model implies that y,
will only be positive given a value of y, greater than zero. The Tobit model assumes the
factors that affect the level of consumption are the same as those that determine the
probability of consumption. See Amemiya (1984) for a detailed review.
Although the Tobit model might be consistent with consumer behavior and might
be useful in studying the consumption patterns of households, it is restrictive in parameter
estimation because it is assumed that both the probability and the level of consumption
are affected identically by the same factors. The Tobit model assumes that the variables
and estimated parameters determine the consumption level as well as the participation
probability. This might not be true. Respondents may have the potential to participate;
however, other reasons might curb consumption. For example, safety issues might not
inhibit shellfish consumption, but reports of contaminated shellfish products might do so
temporarily. This implies that participation and consumption decisions might depend
upon different explanatory variables and parameters, which might have opposite effects
(Lin and Milon, 1993).
The restriction of the Tobit model has been recognized in demand analysis for food
and seafood, including finfish and shellfish, and has consistently been rejected in recent
seafood studies. Cheng and Capps (1988), Lin and Milon (1993), Yen and Huang (1996),
Drammeh et al. (2002), and House et al (2003) all realized the restrictions of using a
Tobit model in demand analysis of seafood. They found that the decision to consume a
seafood product has determinants that are independent of the level of consumption. For
instance, income is expected to have opposite effects on participation and the
consumption of crawfish. Based upon empirical results of previous studies, lower income
households tended to have a higher probability to consume crawfish; however, lower
income households tended to have lower levels of consumption than other crawfish
To accommodate the restrictions of using a Tobit model in analysis for seafood
consumption, a double-hurdle model proposed by Cragg (1971) has been used
extensively in recent studies. In the Tobit model, a variable that increases the probability
of an observation also increases the quantity of consumption simultaneously. In the
model proposed by Cragg, the probability of an observation is independent of the
regression model of the quantity consumed.
Cheng and Capps (1988) used Heckman's two-step procedure, and Yen and Huang
(1996) used a generalized double hurdle model to analyze household demand for finfish.
Lin and Milon (1993) used a count-data double-hurdle model to examine the impacts of
attributes and food safety perceptions of seafood consumption. Drammeh et al. (2002)
and House et al. (2003) also used a double hurdle model similar to Yen and Huang (1996)
to analyze U.S. oyster and catfish consumption, respectively. There are several different
but related models in the mentioned literature; however, all are specified from Cragg's
For crawfish consumption, Yen et al. (1995) also found the complicating feature of
household survey data, which is the significant proportion of zero observations. A large
quantity of zero observations cannot be treated as true non-consumption because zero
observations may be due to, besides non-consumption, infrequency of consumption or
conscientious abstention, which could have other behavioral explanations (Yen et al.,
1995). As a result, the Tobit model also was rejected. The authors separated the sets of
parameters in the probability of consumption and level of consumption equations. To
allow for violation of the distribution assumption of Cragg's double hurdle model, they
used the Box-Cox transformation on the dependent variable, which is an extension of the
We show the benchmark model below using the double-hurdle model framework
specified by Cragg (1971):
Individual i's participation equation can be expressed as
d,* = zia + v, with d,= 0 or 1
Individual i's consumption equation can be expressed as
y = xiP + u,
where y, represents the latent consumption decision, and d, is a latent variable
describing participation. zi and xi are vectors of exogenous variables, and a and P are
parameter vectors. Random errors u, and v, are normally distributed as N(O, 1) and N(O,
a), respectively. It also is assumed that u, and v, are independent.
The double-hurdle model has separate participation and consumption equations that
are related as:
y, = y,* if y,* >0 and d,*>O
= 0 otherwise.
where observed consumption y, relates to latent consumption y,*, only ify,* >0 and d,*>0.
It also is the conditional decision to consume the product (y,* >0).
The double-hurdle model includes two equations: the consumption equationy* and
the participation equation d,*. Thus, the probability of consumption and level of
consumption are determined by separate sets of parameters (a and P). The use of the
same sets of variables, zi and xi, in both equations is not restrictive because these
variables affect consumption and participation differently through the different parameter
coefficient (a and p), and might have opposite effects.
The combination of the above model can be estimated in two parts. A Probit model
can be used to estimate the participation equation, and the parameters of the consumption
equation can be estimated independently using the truncated regression model.
The maximum likelihood estimation of a Probit model is used to evaluate the
censoring rule (zia), given a normal distribution. Since we impose the assumption of a
normal distribution, if y,*>0, then a truncated regression (i.e., truncated Tobit) applies.
Thus, another maximum-likelihood estimation that accounts for a truncated normal
distribution is used for the truncated regression.
The likelihood function for the double hurdle can be derived as
L = YProb(d = 01 zi,a) Prob(d =1 zi,a) f (y, xi,P)
where the 0 under the product sign indicates products over those observations which are
zero, and the + signs under the product sign indicates products over those observations
which are positive, y, >0. For simplicity, Prob denotes the probability, andf(y, -) is the
conditional (truncated) density of y,, given y,>0. a and P are vectors of parameters. As we
indicated, the assumption of independence is imposed, with the participation and
consumption decisions as a binomial probability distribution and truncated at zero
conditional distribution, respectively. The structure of the data determines the specific
forms of the distributions. Because it is beyond the scope of this study, we will not cover
the discussion in this study.
As indicated above, the double hurdle model allows the parameters in the Probit
equation to differ from those in the Tobit model, so that the complete model is a Probit
model for d and a separate truncated regression model for the positive values of y. It is
also assumed in this study that the participation and frequency of away-from-home
crawfish consumption are independent of each other, and the probability and frequency
of crawfish consumption are determined by separate sets of parameters. Since the Tobit
log likelihood is simply the sum of the Probit and truncated regression log likelihood
(Greene, 1995), a test of the Tobit model as a restriction is implemented.
The chi-squared specification test (Greene, 1995)
X = 2(fTobit -fProbit -/Truncated)
is used to determine whether the double hurdle model is a better fit than the Tobit
specification, where is the log-likelihood function value. It is testable with the
likelihood ratio test by estimating the three implied models, with the specific degrees of
freedom, which is equal to the number of variables in x. If the null hypothesis is rejected,
we can conclude that the double hurdle model is a better fit than a Tobit model.
The model was estimated by maximizing the logarithm of the likelihood function
using a modified double hurdle model (Cragg, 1971), with the frequency of away-from-
home consumption of crawfish as the dependent variable. In practical terms, the Probit
model and the truncated Tobit model as well as the compound Tobit model have been
incorporated in many software packages (i.e., LIMDEP, SAS, and TSP). As a result, the
estimation is now essentially on the level of ordinary regression, and will not be covered
in this study.
The marginal effects of the independent variables (similar to the Tobit model), on
the probability of participation, and the conditional level of consumption can be derived
by differentiating the probability and conditional mean, di(z)/l, and ci(y*|y*>0)/a,,
where F(z) and E(y*|y*>0) are the probability of participation and the conditional mean of
consumption, respectively, and x is the specific independent variable. The marginal
effects on the unconditional mean of consumption, which can be associated with all
observations, can be derived by ci(y)/cc, where E(y)=F(z)-E(y*|y*>0). The marginal
effects on the unconditional level evaluate what contributes to the consumption level by
increasing or decreasing either the probability or conditional level. The marginal effects
are computed by LIMDEP "by computing the derivatives for each observation and
averaging the derivatives" (Greene, 1995). Although the approach ignores the fact that
some variables are binary, the results are almost exactly the same as the results of
computation for binary variables using numerical methods (Greene, 1999).
In this study, the dependent variable is the frequency of away-from-home
consumption of crawfish in the last 12-month period. Based upon the discrete nature of
the dependent variable, it is a count data variable. Consequently, instead of using a
continuous double hurdle model, a count data double hurdle model should be considered.
In this study, a count data double hurdle model developed by Mullahy (1986), which is
similar to Lin and Milon's (1993) and Bilgic and Florkowski's (2003), is used.
Truncated-at-Zero Count Data Double Hurdle Model
Because the dependent variable, the frequency of away-from-home consumption of
crawfish, is a count, our analysis adopted the count data double-hurdle model similar to
Lin and Milon's (1993) and Bilgic and Florkowski's (2003). A good review of the
modified count data model for the hurdle model was developed by Mullahy (1986).
According to Bilgic and Florkowski (2003), because of the possible overdispersion
in the observations, the assumption of the familiar Poisson distribution truncated at-zero
might not always fit the sample. However, in this study, we tested the overdispersion and
compared the Poisson and negative binomial distributions of both zero and positive
Compared to the Poisson model, the negative binomial model is not encumbered by
the Poisson's mean=variance nature (var[Y] = E[Y]) (Mullahy, 1986). The variance of a
negative binomial variant can exceed its mean, and the relationship between population
mean and variance of the negative binomial distribution is defined as
var[Y]= E[Y( + OE[Yb
For both the Poisson and negative binomial models, a hurdle (truncated-at-zero)
specification is derived. See Mullahy (1986) for a detailed discussion.
As the result of Mullahy's modification, the binomial probabilities (the
participation decision) are identical to those of a standard binomial Logit model. Thus, it
is appropriate to test both Probit and Logit models for the binary probabilities.
The consumption decision distributes as either a truncated-at-zero Poisson or a
truncated-at-zero negative binomial model, depending on the overdispersion. Again, the
specified model is estimated using standard maximum likelihood techniques, and ML
estimates can be obtained by maximizing the log likelihood function. The compound
model (single decision) and truncated-at-zero model have been incorporated in several
software packages (i.e., LIMDEP). It is worth mentioning here that we included all the
same determinants regarding specific perceptions and preferences, socio-economics, and
demographics, since we have no basis to exclude any variable in either decision.
Issues of Crawfish Consumption
Crawfish consumption tended to vary by region of residence in the targeted
Southeast and the Gulf region (Figure 6-1). Visual inspection shows that consumers in
the West South Central region (AR, LA, OK, TX) are most likely to consume crawfish
both away-from-home and at-home (Figure 6-1). Overall, 39.8 percent of the
respondents from the West South Central region consumed crawfish away-from-home,
compared to 11.6 percent in the northern South Atlantic region (DE, DC, MD, NC, VA,
WV). Chi-squared tests on significance are included below the table. Chi-square
probabilities below 0.05 indicate a significant difference in the variables. In Figure 6-1,
the chi-square probability of 0.001 indicates crawfish consumption is significantly
different in the different regions. The result is consistent with our expectation, since the
majority of crawfish produced in the United States is from the West South Central region
where the consumption rate is expected to be higher than in other regions. The southern
part of the South Atlantic region, including Florida, Georgia, and South Carolina, ranked
second in crawfish consumption.
Farm-raised crawfish production is mainly in the lower Gulf Coast region, such as
Texas, Mississippi, Florida, and Louisiana, with most of the acreage found in Louisiana
(Avery and Lorio, 1999). In this study, crawfish consumers were asked if they were
aware of whether the crawfish they had eaten was farm-raised or not. Only 29 percent of
the crawfish consumers answered they were aware, but among those respondents, over 80
percent had eaten farm-raised crawfish in the previous 12 months. Among those
respondents who had eaten farm-raised crawfish, over 94 percent indicated they would
eat farm-raised crawfish again. Among the remaining crawfish consumers who had not
eaten, or were not aware they had eaten, farm-raised crawfish, over 67 percent indicated
they would be willing to consider consuming farm-raised crawfish. This implies that it
might be appropriate to use educational approaches to promote the farm-raised crawfish
and let the consumers or potential consumers have more knowledge about farm-raised
Northern South Southern South East South Central West South Central
Away-From-Home Consumption 0 Overall Consumption
Note: Chi-square probability < 0.001.
Figure 6-1. Regional percentage of crawfish consumption.
Domestic Versus Imported Crawfish
Wal-Mart in Louisiana carries crawfish produced in China, which even the most
dedicated economists espousing comparative advantage had not forecast. Do consumers
really like imported crawfish over the domestic crawfish? As a special interest of this
study, crawfish consumers were also asked to indicate whether they prefer domestically
produced or imported crawfish. The survey indicates that although 58 percent of the
crawfish consumers did not know where the crawfish they had consumed came from,
about 52 percent of the consumers indicated they preferred locally produced and only six
percent indicated they preferred imported crawfish. A relatively large percentage of
consumers had no opinion, meaning they either do not know or do not care (Figure 6-2).
This implies that properly promoted domestically produced crawfish, targeting those
crawfish consumers, might win back the market share lost to the imported product.
| 30 -
2 0 ------------
Preferred Not Preferred Do Not Care Do Not Know
Domestic Crawfish 0 Imported Crawfish
Figure 6-2. Comparison of preferences over domestic and imported crawfish products.
Since most of the crawfish imported are in the form of tail meat, and domestically
produced tail meat is usually high in price, the product form might explain the reason
why imported crawfish have an increasing market share. In the survey, crawfish
consumers were asked to identify what form of crawfish they prefer: whole crawfish or
tail meat? Live whole crawfish and boiled whole crawfish as well as tail meat are the
main forms of crawfish products normally found on the market. However, in order to
simplify the question and focus on away-from-home consumption, we included only
whole and tail meat product form in this study. The majority of existing crawfish
consumers (72%) indicated that they preferred tail meat to whole crawfish in away-from-
home consumption. Interestingly, although the price of tail meat is comparatively higher
than the price of whole crawfish, a large percentage of consumers (71%) preferred tail
meat to whole crawfish in at-home consumption. This might be caused by the trend of
consumer preferences towards convenience. Also, this implies that the introduction of
new crawfish products targeting consumer trends, such as convenience and health
concerns, could encourage consumption or more consumption to some extent. Domestic
crawfish producers and processors can design marketing strategies accordingly to
compete with imported products.
Additionally, existing crawfish consumers were asked if they preferred fresh or
frozen crawfish. The majority (75%) indicated that they preferred fresh crawfish products,
with only one percent preferring the frozen form and 24 percent having no preference.
This is consistent with the major consumer trend of consuming fresh products. This
implies that domestically produced fresh crawfish can be competitive with imported
frozen products if prices are reasonable. However, it is believed that existing fresh
crawfish products are far more expensive compared to those imported products.
Reasons for Consuming and Not-Consuming
Reasons for consuming
In addition to the frequency of away-from-home and at-home consumption and the
demographic variables, respondents were asked to identify their main reasons for
consuming crawfish. Results from the 220 crawfish consumers (including the 189 away-
from-home crawfish consumers) who responded to this question are illustrated in Figure
6-3. As indicated by about 87 percent of the crawfish consumers and the away-from-
home crawfish consumers, the principal reason for consuming crawfish was enjoyment of
flavor. Next was preference for Cajun style, followed by adding variety to diet (Figure 6-
3). It is worth mentioning that there was no statistically significant difference between
away-from-home consumers and overall crawfish consumers (Chi-square probabilities
ranging from 0.2817 to 0.8813).
Among the 220 crawfish consumers, 138 respondents indicated they only
consumed crawfish away-from-home, 31 indicated they only consumed at-home, and 51
indicated they consumed both away-from-home and at-home. Results from these three
types of consumers who responded to this question are illustrated in Figure 6-4. As
indicated, although the percentage levels are somewhat different for all three types of
consumers, the principal reason for consuming crawfish was enjoyment of flavor. Next
was preference for Cajun style, followed by adding variety to diet (Figure 6-4).
Reasons for not consuming
Both consumers and non-consumers of crawfish were asked to identify the top
three reasons for either not consuming or not consuming more crawfish (Figure 6-5). For
non-consumers, lack of availability of the preferred product form, bad impression, and
smell were the top three reasons for not consuming; however, taste also was ranked high
SAway-From-Home Consumption 0 Overall Consumption
Note: Chi-square probabilities ranging from 0.2817 to 0.8813
Figure 6-3. Categories of reasons given for consuming crawfish (crawfish consumers vs.
C) C)-' .
* ~ e n C) C)-
a e e, C)
W a rH
MAway-From-Home Only OAt-Home Only OAll Crawfish Consumers
Note: Chi-square probabilities between AFH-Only and AH-Only ranging from 0.1707 to 0.9787
Figure 6-4. Categories of reasons given for consuming crawfish (away-from-home
consumers only, at-home consumers only, and all crawfish consumers).
in the reasons for not consuming crawfish. In contrast, crawfish consumers gave
significantly different responses to the questions (Chi-square probabilities < 0.0001).
Price is too high, followed by lack of availability of domestic products and custom were
the top three reasons for not consuming among existing crawfish consumers.
Crawfish Consumers O Non-Consumers
crawfsh (consumers vs. non-consumers).
sh by those nonCrawfish Consumers Non-Consumers
Note: Chi-square probabilities < 0.0001
Figure 6-5. Categories of reasons given for not consuming or not consuming more
crawfish (consumers vs. non-consumers).
We also illustrate the top three reasons for not consuming for away-from-home
consumers and non-away-from-home consumers separately. For non-away-from-home
crawfish consumers, unavailability of product form, bad impression, and smell also were
the top three reasons for not consuming. Taste also was ranked high in the reasons for not
consuming crawfish by those non-away-from-home consumers. Away-from-home
consumers gave different responses towards the question. Price is too high, followed by
unavailability of domestic products and safety concerns were the top three reasons for not
consuming by existing away-from-home consumers. No custom or tradition became the
fourth important reason for not consuming crawfish.
It is worth testing the relationship of reasons for not consuming among non-
crawfish consumers, only away-from-home consumers, and only at-home consumers
(Figure 6-6). For non-crawfish consumers, unavailability of product form, bad
impression, and smell were the top three reasons for not consuming. Taste also was
ranked high in the reasons of not consuming crawfish. Consumers who only consumed
crawfish away-from-home gave different responses towards the question. Price is too
high, followed by unavailability of domestic products and no custom were the top three
reasons. Safety concerns became the fourth important reason for not consuming crawfish
among away-from-home consumers. Interestingly, consumers who only consumed
crawfish at-home gave somewhat different responses to the question. Price is too high
and unavailability of domestic products ranked much higher than the other reasons. No
custom and smell ranked third and fourth. However, safety concerns was not as important
for at-home consumers, who might have been influenced by the fact that they prepare the
Away-From-Home Crawfish Consumption
Consumers were asked to identify how many times they had consumed crawfish
both at-home and away-from-home in the previous 12-month period. However, to focus
on away-from-home consumption, we treat the frequency of away-from-home
consumption as the dependent variable in the count data double hurdle model. Because of
its discrete nature, we reported the sample frequency distribution of the dependent
variable (FREAFH) in Table 6-1. The table shows the number of times a consumer
consumed crawfish away-from-home in the previous 12-month period. Average
consumption of the overall sample (733 responses) was 0.8 times; average consumption
of the 189 away-from-home crawfish consumers was 3.0 times.
2 40 -
H AF- nI O HOI IO No n-CEsu.
B i u! ,a 'S5
EAFH-Only DAH-Only O Non-Consumers
Note: Chi-square probabilities between AFH-Only and AH-Only ranging from 0.1223 to 0.9924.
Figure 6-6. Categories of reasons given for not consuming or not consuming more
crawfish (away-from-home only, at-home only, and non crawfish consumers).
Table 6-1. Sample frequency distribution of the dependent variable (n=733).
Away-From-Home Number of Consumers
Consumption (times) (n=733)
0 544 74.2
1 54 7.4
2 63 8.6
3 24 3.3
4 14 1.9
5 18 2.5
6 3 0.4
7 1 0.1
8 1 0.1
10 5 0.7
12 3 0.4
15 3 0.4
Note: Overall 733 respondents, values indicate the times of away-from-home crawfish
consumption in the previous 12 months period.
The following model was estimated using a count data double hurdle model
developed by Mullahy (1986), with the frequency of away-from-home consumption of
crawfish as the dependent variable. The dependent and independent variables are
described in Table 6-2.
As mentioned in the previous chapter, an interesting and distinctive feature of the
hurdle model is that the probability of participation is assumed to be independent of the
level of consumption. The count data double hurdle model consists of two equations
describing participation and consumption decisions separately. In this study, the
participation equation depicts the decision of whether to be an away-from-home crawfish
consumer, and the consumption equation refers to how many times to consume as an
away-from-home crawfish consumer.
For the participation decision stage, we used a Logit model to estimate the
probabilities of being an away-from-home crawfish consumer. The coefficients from the
Logit model (participation decision) as well as the marginal effects (calculated at mean
value) are reported in Table 6-3. The Logit model correctly predicts a consumers'
likelihood of being or not being an away-from-home crawfish consumers 93.7 percent of
the time (incorrectly predicted being a consumer 3.4 percent of the time and not being a
consumer 2.9 percent of the time). This can be compared to a naive prediction, which
would result in correctly predicting away-from-home crawfish consumption 74 percent of
the time. The prediction rate supports the appropriateness of using a Logit model (with
In the second stage, the dependent variable is a count variable for the number of
times crawfish was consumed away-from-home in the previous 12 months. We have
Table 6-2. Description of variables included in the double-hurdle model.
Variants Variable Name Description
Consumption of Crawfish FREAFH Frequency of crawfish consumption away-from-home
FREAH Frequency of crawfish consumption at-home
Knowledge of Crawfish KNLAN 1 if respondent indicated being aware of the difference between crawfish and
Reasons for consuming The following variables are 1 if this reason was listed as one of the top three reasons for consuming crawfish:
Reasons for not consuming, or
not consuming crawfish more
Region of residence (Gulf
FLAVOR Enjoy flavor
FARMRSD Farm raised crawfish
VDIET Variety in diet
CAJUN Prefer Cajun Style
The following variables are 1 if this reason was listed as one of the top three reasons for NOT consuming, or not
consuming MORE crawfish:
Lack of preferred product form
Lack of availability of domestically produced products
Product safety concerns
Health concerns (allergy)
Northern Southeast Atlantic (DE, DC, MD, NC, VA, WV)
Southern Southeast Atlantic (FL, GA, SC)
East South Central (AL, KY, MS, TN)
West South Central (AR, LA, OK, TX) (omitted category)
Table 6-2. Continued.
1 if Caucasian, 0 otherwise
1 if Black, 0 otherwise (omitted category)
1 if Asian, 0 otherwise (omitted category)
1 if Indian, 0 otherwise (omitted category)
Other race/ethnicity (omitted category)
<$19,999 (omitted category)
$80,000 or above
High School degree or less (omitted category)
2 year college degrees
Degree from college (4 year)
Above college degree
Ages 18-24 (omitted category)
Age 55 or older
1 if currently full time employed
1 if currently part time employed (omitted category)
1 if currently unemployed (omitted category)
1 if student (omitted category)
1 if house worker without pay (omitted category)
1 if retired (omitted catesorv)
considered both truncated-at-zero Poisson and truncated-at-zero Negative Binomial
models for estimation. However, after we tested the Poisson process, the overdispersion
test indicated that the assumption of the Poisson distribution truncated-at-zero could not
be rejected and might fit the sample.' Therefore, we report the results from the truncated-
at-zero Poisson model. Both coefficient estimates and the marginal effects are reported
in Table 6-3 as well as the estimates from a Logit model.
To test the compound (single-decision) count data model (standard Poisson) against
the hurdle count model, we use Vuong's t-test. The standard normal statistics were
calculated. For Vuong's t-test, a value greater than 1.96 favors the altered model. In this
case, the value of 5.66 (given by LIMDEP) was obtained for the null hypothesis that the
standard Poisson and its hurdle Poisson modification are the same. In other words,
Vuong's statistic favors the hurdle Poisson model. The result shows that splitting the
count model is preferred to the standard count model. We also included the single
decision (standard Poisson) estimates in Table 6-3 for comparison.
As expected, results indicated that variables affected the decision to consume
crawfish away-from-home and the frequency of consumption differently. If consumers
ate crawfish at-home more frequently, they were significantly less likely to be away-
from-home crawfish consumers, but their frequency of away-from-home consumption
increased. In other words, as the frequency of at-home consumption increases, the
likelihood to consume crawfish away-from-home decreases. A possible reason for the
1 Overdispersion test: Ho: var[y,]=[; H, var[y,]=[ +ag([1) with g(p1)=[ t-statistic=1.453<1.96; the result
could not reject the null hypothesis at 5% level. See LIMDEP Manual (Greene, 1995) for the
overdispersion test in Poisson regression.
Table 6-3. Empirical results of single-decision and double-hurdle: maximum-likelihood
estimates and marginal effects.
siongle Double Hurdle Count Data
Standard Logit Marginal Truncated Marginal
Poisson Coefficient Effects Poisson Effects
Frequency of Consumption:
Crawfish at-home -0.032*** -0.412* b 0.052**
(0.020) a (0.125) (0.028)
Knowledge about crawfish:
Crawfish and 0.322*
Indicated the following was one of the
Price is attractive
Variety in diet
Prefer Cajun cooking
top three reasons for consuming
Indicated the following was one of the top three reasons for not consuming:
Price too high
No preferred product
Not part of custom
No domestic products
Table 6-3. Continued.
2 year College degree
4 year College degree
Between 18 and 24
Between 25 and 34
Between 35 and 44
Between 45 and 54
East South Central
$80,000 and above
Full time employed
Correct prediction in
Double Hurdle Count Data
Logit Marginal Psn
Co ff ci nt Ef ec s Poisson
Coefficient Effects Pis
a Standard errors of the coefficients are reported in parentheses.
b One, two, and three asterisks indicate significance at the 0.01, 0.05 and 0.10 levels, respectively.
result is that at-home crawfish consumers might be dedicated crawfish consumers, and
they might have preparation knowledge. Compared to eating out, at-home consumption
could be cheaper, and thus made them prefer at-home consumption. However, due to the
fact that they might be dedicated and more frequent crawfish consumers than those who
usually ate crawfish at restaurants, their frequency of away-from-home consumption
increases as their frequency of at-home consumption increases.
Our results indicated that for each one-unit increase in at-home consumption of
crawfish (one unit equals one time in the last 12 months), the respondents were four
percent less likely to be away-from-home crawfish consumers. The average crawfish
consumer ate crawfish away-from-home 2.97 times in the 12-month period. For each
one-unit increase in at-home consumption, respondents increased away-from-home
consumption significantly by 0.08 to 3.05 times.
We did not include the test of the relationship between crawfish consumption and
other seafood consumption (consumption of substitutes) in this study. Further research
could be done to see whether an increase in crawfish consumption will occur at the
expense of other seafood consumption and whether an increase in away-from-home
crawfish consumption will occur at the expense of at-home consumption of other seafood
products. However, in this study we can infer a potential relationship between crawfish
and its substitutes from the information about the sensitivities of crawfish to own-price
and income levels, and the discussion will be covered in the next chapter.
Consumers who know the difference between crawfish and langostino (more
knowledgeable about crawfish) consumed crawfish away-from-home significantly more
frequently. Nevertheless, it did not affect the likelihood of being a crawfish consumer.
Knowledgeable respondents consumed crawfish 0.55 times more often away-from-home
(3.52 times/year). This implies that using educational programs to promote crawfish
could increase away-from-home consumption, but not persuade non-consumers to
Variables representing the respondents' top three reasons for consuming crawfish
as well as the top three reasons for not consuming were included in the model and
provided insight for preferences on away-from-home consumption of crawfish. The
results indicated that those reasons significantly affect both the likelihood to be an away-
from-home consumer and the frequency of away-from-home consumption.
Our results indicated that consumers were more likely to consume crawfish away-
from-home (15 percent more likely) if they selected price attractiveness or availability as
reasons for consumption. Price does matter in crawfish consumption, and this result
infers that crawfish consumption could be comparatively price sensitive. Consumers
were 20 percent more likely to consume crawfish away-from-home if they selected prefer
Cajun cooking as the reason for consuming, but it was insignificant in determining how
frequently a consumer ate crawfish. If respondents indicated they consumed crawfish
because they enjoyed the flavor or for health/nutritional reasons, as expected, they were
33 percent and 12 percent respectively more likely to be an away-from-home crawfish
Frequency of consumption away-from-home was significantly affected by different
variables or in different directions. For example, consumers indicating they consumed
crawfish to add variety to their diet were likely to consume crawfish away-from-home
less frequently. It is interesting to note that if consumers chose crawfish to add variety to
their diet, although they were more likely (20 percent) to be away-from-home consumer,
it decreased the frequency of consumption (0.5 times less than average). This suggests
that someone interested in adding variety to the diet may eat crawfish, but on a less
Frequency of away-from-home crawfish consumption also was influenced by the
variable representing flavor, implying that consumers who selected crawfish because they
really enjoyed the flavor were more likely to consume crawfish more frequently than
consumers who rated other reasons as important. In numeric terms, respondents who
chose flavor as the reason for consuming were 33 percent more likely to consume
crawfish away-from-home, and were likely to consume 0.90 times more. Additionally,
consumers were more likely to consume crawfish away-from-home more frequently if
they indicated health/nutrition as the reason for consuming (0.3 times more).
Variables representing farm-raised crawfish and tradition/habit were not significant
in determining either participation or consumption decisions for away-from-home
Respondents also were asked to identify the top three reasons why they did not
consume or did not consume more crawfish. Probability of away-from-home
consumption of crawfish decreased if the respondents indicated they did not consume
crawfish due to smell or bad impression. However, those two reasons did not influence
the frequency of consumption for existing consumers. Respondents who believed
domestic product unavailability was one of the reasons for not consuming or not
consuming more crawfish were less likely to consume crawfish away-from-home. The
magnitude of these impacts was similar; respondents were 11 percent less likely to
consume crawfish away-from-home because of smell, and 11 percent less likely to
consume because of bad impression. Similarly, consumers were nine percent less likely
to eat crawfish away-from-home because domestically produced crawfish were not
Frequency of away-from-home crawfish consumption was not significantly
impacted by most variables in this category. However, away-from-home crawfish
consumption decreased by 0.57 times if respondents believed price was too high and 0.56
times if respondents had health concerns. The relationship between perceived price
unattractiveness and the frequency of crawfish consumption infers again that
consumption of crawfish is relatively price sensitive. When respondents believe price is
attractive, they are more likely to consume crawfish. On the contrary, when consumers
believe the price is high, they dramatically decrease the frequency of away-from-home
consumption by 0.57 times, a 19.2 percent drop. As a result, we assert that crawfish
consumption is relatively price sensitive.
Additionally, respondents who had a bad impression of crawfish affected both the
probability and the level of away-from-home crawfish consumption significantly. If the
respondents indicated not consuming due to bad impression, they were nine percent less
likely to consume crawfish away-from-home, and consumed 0.47 times less away-from-
Perhaps the most interesting result is that product safety concerns did not influence
either the decision to consume crawfish or the frequency of away-from-home
consumption significantly. This implies that although crawfish scored a bad impression,
it was not due to safety concerns by existing and potential consumers. This result differs
from the pattern of crawfish consumption in other countries such as China. Generally,
Chinese people are more concerned with safety issues due to environmental pollution in
the crawfish production areas.
Demographics had an effect on both the decision and the frequency of away-from-
home consumption. Region significantly impacted the probability and the frequency of
away-from-home crawfish consumption. In general, consumers in the northern part of
the Southeast Atlantic region were significantly less likely to consume crawfish
compared to consumers in the West South Central region. Although not significantly,
consumers in the southern part of the Southeast Atlantic region and the East South
Central region seemed less likely to consume crawfish compared to the consumers in the
West South Central region. This result is consistent with our expectation. Since the West
South Central region is the main crawfish production area in the United States,
consumers in this region tend to have a higher likelihood of consuming crawfish.
Additionally, consumers in the northern part of the Southeast Atlantic region were
significantly more likely to consume crawfish away-from-home on a less frequent basis
(0.88 times less than the West South Central region). However, it is interesting to note
that consumers in the East South Central region (Alabama, Kentucky, Mississippi, and
Tennessee) consumed crawfish away-from-home significantly more frequently than those
in the West South Central region. This implies that although consumers in the East South
Central were less likely to consume crawfish, once they became crawfish consumers,
they consumed more than consumers in the West South Central region. This could
indicate a new target market for the crawfish industry.
One disturbing piece of information delivered by the results is that Caucasian
consumers were significantly less likely to consume crawfish and to consume crawfish
away-from-home less frequently. It is worth noting that education levels did not have a
significant impact on either the participation or the consumption decisions in this study.
However, education levels did have a significant impact on crawfish consumption
according to several previous crawfish consumption studies, and lower educated groups
seemed more likely to consume crawfish and to consume it more frequently. Our survey
had quite a representative sample in terms of education level, and probably was better
than those in other similar seafood and crawfish consumption studies. Further research
with more representative samples might explain the impact of education on crawfish
In our sample, we found that the correlation between education and income was
0.32, but not significant. Also, we found income levels had significant impacts on both
participation and consumption decisions, which partly explains the lack of impact by
education levels. In general, our result indicated that most income groups above the base
group, $20,000-or-less, were about 12 percent less likely to consume crawfish away-
from-home. All income groups above the base group consumed crawfish away-from-
home less frequently, ranging from 0.56 times less (a 18.9 percent drop) to 1.38 time less
(a 46.5 percent drop). This result infers that crawfish consumption is sensitive to income
levels and that crawfish is an inferior good. The lowest income groups have the highest
likelihood to consume crawfish away-from-home and to consume more frequently than
other income groups. People with higher incomes tend to consume less crawfish away-
from-home and to consume less frequently.
Age did significantly influence away-from-home crawfish consumption to some
extent. Compared to the oldest age group (age 55 and above), middle age groups
(between 35 and 44, between 45 and 54) were significantly less likely to consume
crawfish away-from-home. The younger age group (between 25 and 34) consumed
crawfish away-from-home less frequently, and their probability of consuming also
Given that away-from-home consumption might be the main means of introducing
crawfish to potential consumers and that at-home consumption, consumers need more
preparation knowledge, it is important to understand the factors influencing away-from-
home crawfish consumption.
CONCLUSIONS AND IMPLICATIONS
This thesis focuses on developing an understanding of the factors that influence
away-from-home consumption of crawfish in the Gulf region. The main objective was to
analyze the significant factors that influence the probability and frequency of crawfish
consumption, particularly for away-from-home consumption. The information then
could be used by crawfish producers, processors, and marketers to develop market
strategies for growth in the crawfish industry. Also, market trends could be evaluated,
and the crawfish industry could follow the trends found in this study to make marketing
Results showed that the factors that influenced the decision to consume crawfish
away-from-home differed from the factors that influenced the decision of how often to
consume crawfish away-from-home. This is consistent with the results of previous
studies of crawfish and other seafood consumption. The crawfish industry can use this
information to target potential consumers and existing consumers separately. Keep in
mind that one marketing strategy might not work on both groups.
One potential concern about increasing away-from-home consumption is that it
might occur at the expense of at -home consumption. This study found that as the
frequency of at-home consumption increases, the likelihood to consume crawfish away-
from-home decreases. However, as consumers' frequency of at-home crawfish
consumption increases, their frequency of away-from-home crawfish consumption
increases as well.
Price is an important determinant in crawfish consumption. Consumers regarded
price attractiveness as a reason for consuming crawfish, and those consumers were more
likely to be away-from-home consumers of crawfish. Respondents also indicated that
price unattractiveness is the main reason for not consuming or not consuming more
crawfish. Consumers who indicated this dramatically decreased their frequency of away-
from-home crawfish consumption, by 0.57 times, or a decrease of 19.2 percent of the
overall level of consumption in one year. Although quantitative price elasticity was not
available, these results infer that crawfish consumption is relatively price sensitive and
that increasing the price of crawfish will decrease the frequency of away-from-home
crawfish consumption. On the other hand, decreasing the price slightly might encourage
consumption and increase the total revenue for the industry.
The differences in consumer perceptions of crawfish can also be seen through the
relationships of variables representing reasons for consuming and not consuming the
product. Interestingly, product safety concerns did not impact consumers' decisions or
the frequency of consumption. However, having a bad impression of crawfish (i.e., mud
bug) did decrease both the likelihood of being a consumer and the frequency of away-
from-home consumption. This result implies, rather than working on improving crawfish
safety or perception of crawfish safety issues, the industry should work on promoting
crawfish as a farm-raised seafood product. For example, instead of calling it "mud bug"
as it is traditionally called, the industry could call it "miniature lobster" in their
promotion campaign. There is a lack of knowledge about the difference between
crawfish, lobster, and langostino. For instance, of the survey respondents, 70 percent
indicated they do not know the difference between crawfish and langostino, and 22
percent indicated they do not know the difference between crawfish and lobster.
Therefore it might be easy to reposition the image of crawfish in potential consumers'
Our results also indicated that if consumers are more familiar with crawfish, they
would consume more frequently. As a result, work by the industry to increase knowledge
about the product, such as combined demonstrations and educational advertising, could
be successful in increasing the demand for away-from-home consumption.
Compared to average consumers, consumers who ate crawfish to add variety to
their diet were more likely to consume crawfish away-from-home, and they were more
likely to consume crawfish away from home less frequently (0.5 times less per year). In
other words, if consumers choose crawfish to add variety to their diet, they eat crawfish,
but less frequently.
Of particular use to the industry are the results surrounding the variables reflecting
availability. Consumers who knew that crawfish were available were more likely to
consume crawfish. On the contrary, consumers who did not know domestic products
were available were less likely to consume crawfish. Because of the perceived small size
of the crawfish market, not many supermarket chains carry crawfish, and live crawfish
have to be ordered online from Louisiana processors. This implies that the small market
size is not only caused by the lack of demand, but also by the distribution channel, and
the latter one might play a even more important role in the consumption of crawfish. It
appears that a broader distribution channel and more availability might encourage
Additionally, smell was an issue for crawfish consumption, which decreased the
likelihood to consume crawfish by 11 percent. Similar to other seafood products, a fishy
smell is always a big concern. Innovation in the industry would include pre-cleaned, pre-
processed crawfish products such as ready-to-cook tail meat. In general, strategies to
overcome the perceived smell issues could increase demand. This might work,
particularly for at-home consumption. As with other seafood products, the impact of
smell should not be ignored, although the magnitude of the impact on away-from-home
consumption is less than the impact on at-home consumption. Persistent smell issues are
related to bad impression, which could seriously impact both participation and
Relationships seen in the demographics are generally consistent with a priori
expectations with the exception of education level. The relationships between income
levels and away-from-home consumption tell an important story. The lowest income
group, $20,000 and under, has the highest likelihood and frequency of crawfish
consumption. As income increases, people tend to be less likely to consume crawfish
away-from-home and to consume it less frequently. For example, the highest income
group, $80,000 and above, consumed crawfish away-from-home 1.38 times less
frequently than the lowest income group, a decrease of 46.5 percent. This result infers
that crawfish is an inferior good, although a quantitative income elasticity is not available.
This is not the result the industry wants to see, but the information can help the industry
to further stratify consumer segments and to work on segments effectively. How to
transfer crawfish from an inferior good to a normal good becomes a must for the industry
if they want to encourage consumption of crawfish among higher income groups.
Strategies such as differentiating by value adding characteristics to processed crawfish
products could be successful.
Additionally, the information on inferior goods and the sensitivity of price and
income levels on crawfish can infer a potential relationship between crawfish and its
substitutes using Euler's theorem (e,px+ e,py+... + e,p, + ex, =0). Although the price and
income elasticities are not calculated, the empirical result makes an assertion that
crawfish tend to have many substitutes and/or is sensitive to the price changes of
substitutes, given the relatively large hypothetically positive values of ex,py, ex,Pz, and in-
between cross price elasticities implied by the theorem. The industry should design
appropriate marketing-specific strategies to compete with other seafood products. For
instance, differentiation and adding value characteristics to crawfish products, (i.e.,
flavored, ready to cook crawfish tail meat) to reduce the number of substitutes could win
Not much can be said on age groups. The oldest age groups were more likely to
consume the product away-from-home and to consume frequently away-from-home. One
possible explanation is because of the lifestyle of the older segment. This finding is not a
trend that an industry would like to see since younger consumers often set future trends.
Crawfish consumption often is seen as regional because the regions where crawfish
is mainly produced are significantly more likely to consume crawfish. Interesting though,
was the finding that the East South Central region was significantly likely to consume
crawfish away-from-home most frequently.
Another finding in this study is that Caucasians are either less likely to consume or
to consume crawfish less frequently away-from-home. Crawfish consumption is
traditionally associated with ethnic culture and Cajun cooking in this country. This might
be the reason why Caucasians still have lower participation and consumption rates.
However, in recent years, ethnic food has become increasingly more popular, with more
and more people enjoying Cajun cooking, including crawfish. Our study found that the
dislike of taste of crawfish was not the significant reason for not consuming crawfish, and
preferring Cajun cooking was the second reason for consuming crawfish. However, due
to the fact that this study had a larger percentage of Caucasians responding than what is
representative, further study into this issue would be useful.
In this study, we found that patterns of away-from-home crawfish consumption
differ from at-home consumption and other seafood consumption. Crawfish consumption
tends to vary by region of residence, and consumers from the main production regions are
more likely to consume crawfish. Consumers prefer farm-raised and domestically
produced crawfish. Fresh crawfish and tail meat are preferred because of convenience
and freshness. In addition, factors regarding consumer preferences and perceptions
influence participation and consumption decisions differently.
Crawfish consumption is relatively price sensitive, as respondents indicated price is
one of the reasons for consuming and the main reason for not consuming. Crawfish is
perceived as an inferior good, and away-from-home crawfish consumption is relatively
sensitive to income level. Higher income groups are less likely to consume crawfish
away-from-home and to consume it less frequently. In addition, crawfish may have
many substitutes and is relatively sensitive to consumers' income levels.
We also found that dislike of taste is not a significant factor influencing away-
from-home consumption and that nutrition issues tend to positively affect both the
probability and the frequency of away-from-home crawfish consumption. Consumers do
not feel product safety is an issue for crawfish. However, the bad impression of crawfish
decreases both the probability and frequency of away-from-home consumption. There is
a lack of knowledge about the differences between crawfish, lobster, and langostino
among consumers. If the industry can improve the image of crawfish and increase
consumers' familiarity with crawfish, away-from-home, as well as at-home, crawfish
consumption would increase as a result. Our results found availability is a critical factor
to increase crawfish consumption. The industry should increase the availability of
crawfish through different distribution channels in order to encourage consumption. In
addition, smell is a concern of consumers. Product innovation in the industry can be used
to reduce this concern.
In terms of demographic factors that influence away-from-home crawfish
consumption, we found education level and household size do not impact either the
probability or frequency of away-from-home crawfish consumption. Other demographics,
such as age, race, and ethnicity, also influence both probability and frequency of away-
from-home crawfish consumption. Older age groups are more likely to consume crawfish,
while Caucasians are less likely to consume crawfish and to consume it less frequently.
Since the International Trade Commission imposed Less Than Fair Value (LTFV)
tariffs on imported crawfish in 2000, it appears there are opportunities for domestically
produced crawfish to increase its market share. The findings of this study could be used
by the industry to target potential and existing crawfish consumers and to increase
crawfish consumption, specifically away-from-home consumption.
For existing consumers, product development, which focuses on developing new
products for present customers, and market penetration, which focuses on improving
existing products fro present customers, can be used to increase crawfish consumption.
Increasing consumption among existing consumers could be less costly than attracting
new consumers. The crawfish industry could use the findings of this study to target
potential consumers to encourage consumption of crawfish, particularly away-from-home
consumption. Although it is a little costly, it is necessary for the long-term development
of the industry.
The industry should target the regions surrounding the main production region and
promote crawfish as domestically farm-raised seafood product. The study found that
once consumers in other regions start to eat crawfish, they consume it more frequently.
In addition, the industry should increase the availability of crawfish products, particularly
tail meat, through different distribution channels to reach consumers.
Since crawfish may have many substitutes and is perceived as an inferior good, it is
appropriate for the industry to develop new products with value adding characteristics to
differentiate crawfish from its substitutes and to market it as a normal good. Product
innovation (i.e., ready to cook tail meat products) can be successful in marketing crawfish.
Our study also found crawfish to be relatively price sensitive. As a result, carefully
pricing crawfish products, particularly tail meat, is very important in increasing crawfish
consumption and in competing with imports of crawfish and other seafood products.
Appropriate promotions, such as demonstrations, educational advertising, and
repositioning the image of crawfish in consumers' mind, will also be successful in
increasing the demand for crawfish.
As a result of this study, some areas identified that need further research include
quantitative price and income elasticities, the relationship between crawfish and other
seafood products (would increases in crawfish consumption occur at the expense of other
seafood products), and consumption patterns of different races and ethnicities. In
addition, more balanced sample data are needed for further study. It is believed that an
appropriate interpretation of the research findings and the development of related
marketing strategies could win back the domestic market share lost to Chinese imports,
and that the opportunity still exists for the domestic crawfish industry.
2004 MARKET SURVEY OF FOOD CONSUMPTION
Notice: Any information reported below is strictly confidential. This data will be used
only by persons engaged in this survey, and will not be disclosed or released to others for
Directions: Please have the member of the household that usually decides what food you
purchase fill out this survey. Thank you in advance for taking the time to fill out this
Crawfish are crustaceans with a hard outer shell, which provides some protection and
gives rigidity to their bodies. The shell of adults is dark red to nearly black with a wedge-
shaped stripe on the abdomen. These small crustaceans are related to lobsters and closely
Common Names: Red Swamp Crayfish, White River Crayfish, Crawfish.
Scientific Names: Procambarus clarkii, Procambarus zonangulus, Procambarus
paeninsulanus, P. alleni.
Figure A-1. Crawfish pictures.
1. Do you feel that crawfish & lobster are different?
[ Yes (different) [ No (same) [ Do not Know
2. Do you feel that crawfish & langostino are different?
D Yes (different) D No (same) [ Do not Know
3. Have you ever eaten crawfish?
a Yes a No
4. Have you eaten crawfish in the last 12 months?
a Yes a No
5. How many times have you eaten crawfish in the last 12 months? (Please write the
6. Thinking of the occasions you ate crawfish over the past 12 months, how many
times did you eat crawfish in each of the following locations?
times at home times at restaurants times
at other away-from-home locations
7. Are you aware of whether the crawfish you have eaten was farm-raised or wild-
1 Yes (Know) 1 No (Don't know)
If YES, have you ever consumed farm-raised crawfish?
1 Yes 1 No I Do not know
If YES, would you consume it again? D Yes D No I Do not care
If NO, would you consider consuming farm-raised crawfish?
1 Yes 1 No I Do not care
8. Are you aware of where the crawfish you have consumed came from? (Check any
of the following options that apply)
D Domestic 0 Imported D Do not know
9. Would you be more likely to consume crawfish that was produced locally or in the
region? (Check one)
I Yes D No I Do not care 0 Do not know
10. Would you be more likely to consume crawfish that was imported? (Check One)
0 Yes D No I Do not care 0 Do not know
11. What product forms of crawfish do you normally consume Away-From-Home?
(Check all that apply)
D Whole with head D Tail meat only
If you could choose, which form would you prefer? (Check one)
D Whole with head D Tail meat only
12. What product forms of crawfish do you normally consume At-Home? (Check all
D Whole with head D Tail meat only
If you could choose, which form would you prefer? (Check one)
D Whole with head D Tail meat only
13. Do you prefer fresh or frozen crawfish? (Check one)
D Fresh I Frozen 0 Do not care
14. What price would you pay for one-pound of whole crawfish? (See below for typical
15. What price would you pay for one-pound of tail meat? (See below for typical prices)
(Typical prices are: Boiled Whole Crawfish, Medium $3.00 to $5.00 per pound, Large
$6.00 to $7.00 per pound; Tail meat $10.00 to $14.00 per pound).
16. For Away-From-Home consumption, check the top three reasons you EAT
0 Enjoy Flavor and Taste
0 Enjoy Texture
1 Health/Nutrition Benefits
0 Price (Cost compare to other seafood)
D Variety in Diet
0 Prefer Cajun Style
17. Please check the top three reasons you DO NOT EAT crawfish (or do not eat it
[ Don't like the Product Form
I Health/Nutrition Benefits
D No custom
[ Don't like texture and taste
[ Don't like smell
[ No local farm-raised available
0 Concern about safety
D Bad impression (i.e., mud bug)
D Health reasons
18. Gender: 0 Male 0 Female
19. Your Age?
20. Marital status:
0 Never Married D Married
D Separated/Divorced D Widowed
21. What is the highest level of education you have completed?
D No formal education 0 Less than high school diploma
0 High school diploma 0 University undergraduate degree
D University postgraduate degree 0 Other, please clarify
22. Current Employment:
0 Full time 0 Part time 0 Current not working
D Student I Unpaid family worker I Retired
23. Please indicate your approximate household income before taxes:
0 Less than $20,000 0 $20,000 to $39,999 O $40,000 to $59,999
O $60,000 to $79,999 O $80,000 to $99,999 O $100,000 to $119,999
O $120,000 to $139,999 O $120,000 to $139,999 O More than $140,000
24. Number of children under 16 living at home (If none, put 0):
25. Number of people currently living in your household (including yourself)?
26. Please indicate your race (Check all that apply):
D White 0 Black and African American 0 Asian
0 American Indian D Other, please clarify
27. Are you of Hispanic descent? D Yes D No
28. Please list your Religion: (If Not Applicable, please write down None)
29. What is your zip code?
Thank you for your time and effort completing this survey. Please be assured that all
answers will be kept strictly confidential and used only for the purposes of this research.
If you have any questions about the survey, please contact us at (352) 392-1826 or send
email to email@example.com.
LIST OF REFERENCES
Amemiya, T. (1984). Tobit Models: A Survey." Journal ofEconometrics, 24, 3-61.
Avery, J. and Lorio, W. (1999). "Crawfish Production Manual." Pub. 2637. Louisiana
State University Agricultural Center, Baton Rouge, LA (July).
Bilgic, A., and Florkowski, W. (2003). Truncated-at-Zero Count Data Models with
Partial Observability: An Application to the Freshwater Fishing Demand in the
Southeastern U.S." Selected Paper presented at the Annual Meetings of the
Southern Agricultural Economics Association. Mobile, AL (February). Retrieved
February 8, 2004 from http://agecon.lib.umn.edu/.
Cheng, H., and Capps, 0. Jr. (1988). "Demand Analysis for Fresh and Frozen Finfish and
Shellfish in the United States." American Journal ofAgricultural Economics, 70,
Cragg, J. (1971). "Some Statistical Models for Limited Dependent Variables with
Application to the Demand for Durable Goods." Econometrica, 39, 829-844.
D'Abramo, L. R., Ohs, C. L., Hanson, T. R., and Montanez, J. L. (2002). "Production of
the Red Swamp Crayfish in Earthen Ponds without Planted Forage: Management
Practices and Economics." Bulletin 1115. Mississippi Agricultural & Forestry
Experiment Station, Mississippi State University, Mississippi State, MS (February).
Dellenbarger, L. E., August, P., and Schupp, A. (1996). "Boiled Crawfish Consumption
in Louisiana." Journal ofFood Distribution Research, (February), 99-101.
Drammeh, L., House, L., Sureshwaran, S., and Selassie, H. (2002). "Analysis of Factors
Influencing the Frequency of Catfish Consumption in the United States." Selected
Paper presented at the Annual Meetings of the American Agricultural Economics
Association, Long Beach, CA (July). Retrieved November 19, 2003 from
Florida Department of Agriculture and Consumer Services [FDACS]. (1992).
"Aquaculture Species Resource Series: Crawfish." FDACS, Tallahassee, FL.
Florida Department of Agriculture and Consumer Services [FDACS]. (2001). Agriculture
Press Release. FDACS, Tallahassee, FL (September). Retrieved April 19, 2003
Florida Department of Agriculture and Consumer Services [FDACS]. (2003).
Aquaculture Producer Database. Division of Aquaculture. FDACS, Tallahassee, FL.
Food Marketing Institute [FMI]. (2003). Consumer Trends in the United States. Food
Marketing Institute, Washington, D.C. Retrieved December 23, 2003 from
Greene, W. (1995). Limdep Version 7.0 User 's Manual. Plainview, NY: Econometric
Greene, W. (1999). Econometrics Analysis 4t Edition, A LIMDEP Guide to the Examples.
Upper Saddle River, NJ: Prentice Hall.
House, L., Hanson, T., and Sureshwaran, S. (2003). "U.S. Consumers: Examining the
Decision to Consume Oysters and the Decision of How Frequently to Consume
Oysters." Journal of.\ l//llip Research, 22(1), 51-59.
International Trade Commission [ITC]. (1997). "Crawfish Tail Meat from China."
Investigation No. 731-TA-752, Publication 3057. International Trade Commission,
Keithly, M. R. (1985). "Socioeconomic Determinants of At-Home Seafood Consumption:
A Limited Dependent Variable Analysis of Existing and Latent Consumers."
Unpublished Ph.D. dissertation. University of Florida, Gainesville, FL.
Ladewig, F. K., and Schaer, L. S. (1993). "Crawfish-A Healthy Choice." SRAC
Publication No. 243. Southern Regional Aquaculture Center, Stoneville, MS
Larkin, S., Degner, R. L., and Rubinstein, W. (2002). "Market Preferences, Wholesale
Demand & Breakeven Prices for Marine Ornamental Fish Cultured and Collected
in Florida." Staff PaperSP-02-5, Department of Food and Resource Economics,
University of Florida, Gainesville, FL (73pp.). Retrieved December 23, 2003 from
Larkin, S., Tucker, J.E., and Degner, R.L. (2001). "Developing an Internet Survey
Instrument: Application for Florida Sea Grant Marketing Study." Staff Paper SP-
01-8, Department of Food and Resource Economics, University of Florida,
Gainesville, FL (20pp.).
Lin, C. T., and Milon, J.W. (1993). "Attribute and Safety Perceptions in a Double-Hurdle
Model of Shellfish Consumption." American Journal ofAgricultural Economics,
McCullough, A., Gempesaw. C. M. II, Daniels, W. H., and Bacon, J. R. (2001).
"Simulating the Economic Viability of Crawfish Production: A Two-stage
Modeling Approach." Aquaculture Economics and Management, 5(1/2) 2001: 69-
Mullahy, J. (1986). "Specification and Testing of Some Modified Count Data Models."
Journal ofEconometrics, 33 (December), 341-365.
National Fisheries Institute [NFI]. (2003). "About Our Industry." The Fish and Seafood
Trade Association, NFI, Arlington, VA (March). Retrieved April 19, 2003 from
Nicholson, W. (2002). Microeconomic Theory: Basic Principle and Extensions (8th
edition). Mason, OH: South-Western Educational Publishing.
Roberts, J. K. (2000). "Imported and Consumer Impacts of U.S. Antidumping Tariffs:
Freshwater Crawfish from China." Research Summary, Department of Agricultural
Economics and Agribusiness, Louisiana State University Agricultural Center,
Baton Rouge, LA.
RoperASW (2002). Food Trends in America Presentation. RoperASW, New York, NY.
Retrieved December 23, 2003 from http://www.roperasw.com/.
Schupp, A., Pomeroy, R., and Dellenbarger, L. (1991). "U.S. Food Store Experience in
Handling Crawfish." Journal ofFood Distribution Research, (June), 1-9.
Selassie, H., House, L., and Sureshwaran, S. (2002). "Characteristics and Consumer
Preferences Affecting Marketing of Farm Raised Fish." Research Monograph.
South Carolina State University, Orangeburg, SC (December).
Tobin, J. (1958). "Estimation of Relationships for Limited Dependent Variables."
Econometrica, 26, 24-36.
U.S. Census Bureau (2000). U.S. Census 2000, Washington, D.C. Retrieved February 24,
2004 from http://www.census.gov/main/www/cen2000.html.
U.S. Department of Agriculture, Economic Research Service [USDA-ERS]. (1999a).
"Contribution of Away-From-Home Foods to American Diet Quality." Research
Summaries, Family Economics and Nutrition Review, 12 (3, 4). USDA-ERS,
U.S. Department of Agriculture, Economic Research Service [USDA-ERS]. (1999b).
"Aquaculture Outlook." USDA-ERS, Washington, D.C.
U.S. Department of Agriculture, Economic Research Service [USDA-ERS]. (2002a).
Food Consumption Trends: Food Consumption (per capital) Data System. USDA-
ERS, Washington, D.C. Retrieved May 19, 2003 from http://www.ers.usda.gov/.
U.S. Department of Agriculture, Economic Research Service [USDA-ERS]. (2002b).
"Food Away From Home." Food Market Indicators, Food CPI, Prices and
Expenditure: ERS Food Expenditure Tables. USDA-ERS, Washington, D.C.
Retrieved May 19, 2003 from
U.S. Department of Agriculture, Economic Research Service [USDA-ERS]. (2002c).
Food Consumption (per capital) Data System. USDA-ERS, Washington, D.C.
Retrieved May 19, 2003 from http://www.ers.usda.gov/.
Yen, T. S., and Huang, L. C. (1996). "Household Demand for Finfish: A Generalized
Double-Hurdle Model." Journal ofAgricultural and Resource Economics, 21, 220-
Yen, T. S., Dellenbarger, L. E., and Schupp, A. R. (1995). "Determination of
Participation and Consumption: The Case of Crawfish in South Louisiana." Journal
ofAgriculture and Applied Economics, 27(1), 253-262.
Xumin Zhang was born on November 19, 1972, in China. After graduating from
high school, he enrolled in the Food Science and Technology Department at the Shanghai
Fisheries University, Shanghai, China, in 1991, and graduated with a bachelor's degree in
science in June 1995.
In September 2000, after working several years with Metro, a German supermarket
chain in China, Mr. Zhang immigrated to the United States and continued his education.
After studying at Santa Fe Community College, Gainesville, Florida, for one and one-half
years, Mr. Zhang was accepted in the Master of Science program of the Food and
Resource Economics Department at the University of Florida. He began his master's
study at the Food and Resource Economics Department in August of 2002, with fields of
specialization in food marketing and management.