Impacts of purchase preference of urban resident on safe-certified pork in Beijing of China

This study aims to analyze the factors which influence the consumers purchase preference and their impacts on certified pork by using Beijing urban residents’ questionnaire survey data in December 2010. We first investigate some impact factors based on the consumer’s decision process model, and did the regression analysis by means of binary logistic model, and then calculate the marginal effect coefficients. Our results suggest that economic constraint of income and higher price of safe certified products are still important factors affecting consumer’s purchase preference for certified pork, and that consumer’s perception of the current quality safety risks of pork market and knowledge about certified pork also have significant impacts on the consumer’s purchase preference for certified pork products.


INTRODUCTION
The increase of Chinese consumer's income and the food safety issues led to the demand surge of safequality agricultural products.The industry development policies of pollution-free food, green food and organic food that were formulated in the late 1980s enhance the safety of food supply smoothly.
Nowadays, safe-quality agricultural products are rapidly increasing with recent data indicating annual average growth rates of 10 to 15% in China (NBS, 2009).With the outbreak of a series of food safety scares, such as mad cow disease scandals and melamine contamination in milk powder currently, consumers' confidence and demand for safe-quality food has steadily dropped.There is a clear link between the mad cow disease scandals and the beef consumption decrease sharply (Wallace et al., 2005).Ensuring food safety has therefore become a global issue for governments of all countries.
The agricultural market is a lemons market that typically emerges as a result of market failure during information transmission and which drives the safequality food out of the market or result in an inefficient allocation.The lemons problem, such as food with experience or credence characters, is important in the food sector and markets for products.The quality guarantee from a third party and traceability networks are used to bridge the information gap between buyers and sellers, and to reduce inefficiencies due to asymmetric information (Piggott and Marsh, 2004;Ortega et al., 2011).Unlike some developed countries, Chinese food safety systems are regulated by several government entities which sometimes overlapping their responsibilities.
The problems of small-scale farmer production, lack of severe regulations and imperfect supervised systems lead to spread restriction of safe-quality food in China.As a result, it is not easy for Chinese consumers to foster a stable purchase preference for third-party certification and a quality-specific information label products.
In this context, the assessment of Chinese purchase preference for safe-quality agricultural products may significantly improve the effectiveness of food safety regulation for policy makers, and provide better insights into consumer's behaviors for the producers.
Based on consumer's decision process model, the paper uses the questionnaire survey data about Beijing urban residents in December 2010 and analyzes the impact factors of the consumers purchase preference and their influences on certified pork products.

A FRAMEWORK AND EMPIRICAL MODEL
A framework of theoretical model For centuries, pork has always been the primary animal protein source in Chinese diets.Pork consumption has dramatically increased for more than three times from 1980 to 2008.As their incomes getting higher, Chinese consumers now shift consumption away from grains and legumes toward safe-quality livestock products.At present, safe-certified pork products are popularized in large and medium-sized retail markets.Taking the fresh safe-certified pork as example, we analyze the factors affecting consumer's purchase preference for the certified products.According to the consumer's decision process model, consumer's purchase behavior is a reaction driven by a certain demand and motivation.
The consumer's purchased decision can be divided into induced demand stage, information searching stage, purchase decision stage and post-purchase evaluation stage based on the sequences of purchase behaviors.Each consumer's purchase decision is a process of learning and re-recognizing which take the shape of new attitudes about purchased products.This attitude will impact consumer's repurchase behaviors that form a cycle of purchase decision process.
At the induced demand stage, consumer's concern about food safety issue leads to increased demand for wholesome foods.Previous research shows that foodsafety perceptions are important considerations that can have an impact on food choice (Grunert, 2005).With the growing concerns over food safety risks, Chinese consumers now are aware of health and involved with nutrition, and adopt a healthy eating habit (Kraft and Goodell, 1993).In addition, they have preference for buying high quality, nutritious, healthy foods which help enhance well-being, and avoid foods with additives or preservatives (Harper and Makatouni, 2002;Rembiakowska, 2007).
At the information searching stage, consumers search attributes about agricultural internal quality to make a rational purchase decision in imperfect market with asymmetric information.Being lacking of requisite information about the quality of agricultural products, consumers reduce their trust and willingness--to-pay for safe-quality products.Briz and Ward (2009) investigate the Spanish consumption behaviors of organic food, and find that with the rising of consumer's cognition about organic food, the consumption ratio of organic food had been increased quickly.When the cognition reached a certain level, the Han et al. 10409 consumption ratio began to decline gradually.Loureiro and Umberger (2005) find that the desirable food country-of-origin labeling program is the most important factor affecting consumers purchase behaviors.Loureiro and Umberger (2003) indicated that compared with common steak and hamburger, American consumers were willing to pay much more for steak and hamburger labeled as "U.S. Certified Steak" and "U.S. Certified Hamburger", which was equivalent to an increase of 38% and 58% respectively.Food traceability system is an important signal for the manufacturers to transmit safequality information to the consumers (Caswell, 1998).The more consumers know about quality-certification products, the more likely they would purchase these products.It is a rational choice for consumers to buy the products with which they are familiar to reduce the search costs (Yi and La, 2004).
At the actual purchase decision stage, consumers' choice mainly depends on their preferences and the prices of safe-quality agricultural products.Lusk and Schroeder (2004) and Alfnes et al. (2006) designed a real choice experiment market with posted prices to investigate consumers' WTP and real preference for food quality attributes.Recently, the prices of safe-certified agricultural products in Beijing are almost twice as much as those of ordinary products; therefore, low-income consumers have to spend less on these high-price foods and buy ordinary goods with far less prices.Interestingly, previous research reports conflicting findings with regard to the impact of price on consumption of organic food.Verhoef (2005) finds that price affects purchases of organic meat among Dutch consumers.Briz and Ward (2009) also find that demand for organic produce declines when it is perceived as expensive.However, Tarkiainen and Sundqvist (2005) do not find a significant effect of price on purchase intention regarding organic produce.Some studies confirm that consumers who pay higher premium for organic apple were more likely to purchase these certified food (Loureiro et al., 2003).
The process of consumers' purchase decision cannot finish with the end of consumption.After consuming the product, consumers compare its actual quality with their expectation.At this post-purchase evaluation stage, consumers accumulate experience for repurchase behavior.The higher trust and valuation, the more inclination consumers have to purchase these safe-quality products.Besides, trust can reduce perceived risk on the acceptance of new product technology, other research shows that there is a positive and significant effect between trust on gene technology and purchase behavior (Rosati and Saba, 2000).
Consumers' socio-demographic factors such as household income, age, gender, marital status, education level and the presence of children under 16 affect individuals' perceptions, attitudes and behaviors in the context of agricultural produce consumption.Wandel and Bugge (1997) find that compared with younger consumers, older consumers concern more about health when buying organic produce.Tumer et al. (2011) conclude that there is a positive relationship between cheese consumption and marital status.Thompson (1998) points out that the highest percentages of consumers buying organics are aged 18 to 29 and the least likely being 60 years old and above.He also found positive correlation between education and organic purchases behavior.Based on the consumer's decision process model, we draw on this framework of the determinants of food choice in framing our theoretical model (Figure 1).

Specification for empirical model
Unlike other home appliances such as automobiles, agricultural products are of higher purchase frequency with short-time interval.Previous studies analyze consumers' purchase behavior for certified agricultural products in experiment or real market, which cannot reflected their stable purchase preferences.Therefore, we investigate the respondents' purchase cases about fresh pork including certified pork and uncertified pork in recent one month, and their recall of certified fresh pork purchase behavior in the year of 2010, and then assess the consumers' certified pork purchase proportion.We assume that if the consumers' purchase of certified pork is more than half of the total fresh pork consumed daily, they have purchase preference for fresh certified pork.We set up the following equation: In Equation ( 1), y is 0 if the daily purchase proportion of certified pork is less than half of total fresh pork for an individual consumer; y equals 1 if the proportion is more than half of total fresh pork. 1 x , 2 12 x x L , , represent impact variables.The paper uses binary logistic model to do the regression analysis and the model form is: We can rewrite the Equation (2) as: In Equation (3), i p represents the probability of the ith consumers has purchase preference for fresh certified pork.
In order to take further study the probability change of consumer's purchase preference when explanatory variables change one unit, the paper established the From Equation (4) we will see that the marginal effect is the product of the logistic distribution density function estimated in the model and each regression coefficient.

DATASET AND DESCRIPTIVE STATISTICS
Data were gathered from consumers' questionnaire surveys in December 2010.Combining with economic development level, population characteristics, distribution of major shopping malls and supermarkets in Beijing, we select typical survey districts such as Haidian District, Chaoyang District, Fengtai District, and Changping District, and choose 2 to 3 supermarkets such as Carrefour, Chaoshifa, Lotus Supercenter in Beijing of China, shopping malls, residential squares or agricultural products retail market from each district.Our respondents are main buyer of food for the household.
The survey gathers 611 valid samples.
The samples comprise 454 (74.3%) females, and 85.9% of the samples are married.More than half of the samples are aged between 21 and 40 (57.7%).The samples' educational level is mainly concentrated in high school and university degree.50.7% samples' monthly household income ranged from 4001 to 6000 RMB.44.7% samples are employed in enterprises.Table 1 provides details of the sample characteristics.
Our sample is comparable to Beijing Census by Beijing Statistics Bureau 2010 in terms of age, monthly household income, occupation and family scale.However, the samples' educational level is higher than the average level of the Beijing Census statistics which is features common to many other surveys.

Variables explained
dependent variable in the model is the probability of whether or not the consumer has purchase preference for certified pork products.This study has 12 explanatory variables, of which the descriptive statistics analysis is shown in Table 2.The interpretations for some of the explanatory variables are given.
Consumer's knowledge about certified agricultural product: There are three kinds of certified marks designed in the questionnaire; There is no safe-quality risks=1, There are a less safequality risks=2, Uncertain=3, There are some safe-quality risks=4, There are strong safe-quality risks=5 3.42 0.89 green food, pollution-free food and organic food.We design somequestions about certified product symbols, certification procedures, quality control processes and inspection standards in order to investigate consumer's knowledge about certified agricultural products.The consumer's trust in the quality of certified pork products: This paper designed "Do you believe that the pork marked with qualitycertified marks is strictly produced in accordance with the certification standards?",and consumers could choose from five options, such as "totally distrust, slightly distrust, do not know, slightly trust, completely trust" which respectively valued 1 to 5 according to Likert-type scale.
The higher value indicates that consumers have higher trust in pork products.Consumer's willingness-to-pay (WTP) for certified pork products: Based on the market researches in the typical supermarkets and shopping malls in Beijing, we evaluated the prices of three kinds of certified pork products, respectively as 36, 50 and 64 RMB/kg.If the respondents think that the certified pork price is too high, then they will continue to investigate their willingness-to-pay for this kind of certified pork product.If that price is within the scope of their ability to pay, then their willingness-to-pay would be the current estimated price of this kind of certified pork.Consequently, the average payment for the three kinds of certified pork is their willingness-topay for the certified pork products.
Consumer's perception about the current safe-quality risks of pork market: We designed in the questionnaire that whether or not consumers think the fresh pork products exist safe-quality risks in market of Beijing.The study devises five relative answers to value consumer's perception according to Likert-type scale.The higher the variable is valued, the more safe-quality risks the consumers think.

Consumers purchase behaviors statistics analysis
Livestock consumption of majority the respondents is pork products (74.3%).Only 20.1% samples whose daily purchase proportion of fresh certified pork is more than half of total fresh pork which shows that, despite urban residents take pork product as their major source of animal proteins in Beijing at present, buying ratio of certified pork products is still low.
The quality information of the fresh pork products that consumers give preference is reported in Table 3. 342 samples take the certified marks of agricultural products as their primary purchase basis (55.9%), followed by the manufacture date and the price of the pork product.
The three factors in the last place successively are the convenience and health of sale place, the pork products' nutrition and taste.Among 342 sample consumers who stated preference for certified pork products, only 94 samples showed that the daily purchase proportion for certified pork were more than half of total fresh pork products.These data show that in spite of the fact that consumers stated their preference for certified pork products at present, only a handful of consumers turn the potential purchase intention into actual purchase behaviors.The correlations of consumer's characters and his purchase preference are presented in Table 4.The females have much more purchase preference for certified pork products compared with the males.The ratios of unmarried and married consumers having purchase preference are 29.07 and 18.67, respectively.In the view of the distribution of age groups, consumers between the ages of 41 to 50 make up the largest proportion of people having purchase preference, and the consumers aged 31 to 40 years old have the smallest proportion of preference for certified pork products correspondingly.
When the education level is taken into account, there are 50% consumers having master degree and above foster the actual purchase preference, but high-school graduates make up the smallest proportion with 7.73%.
As to the group of the monthly household income, the lowincome consumers (monthly household income less than 6000 RMB) have the least ratio whereas the high-income consumers (monthly household income more than 16001 RMB) have the largest proportion of purchase preference with 82.14%.
Regarding to the consumer's knowledge about certified agricultural products, 31.71% of the consumers having high-level knowledge (they can answer more than 10 questions correctly) and only 10.29% of the consumers having the low-level knowledge (the number of their correct answer is less than 6) hold purchase preference for certified pork products.
The willingness-to-pay for certified pork products and their respective ratio to present market price are given in Table 5.The ratio of willingness-to-pay to present market price for three certified pork products (pollution-free food, green food, and organic food) are 87.5, 79.1 and 74.2%, respectively.The difference between consumers' willingness-to-pay for the organics and its relative market price is larger than the other certified products.Besides, the consumers who have higher willingness-to-pay for certified pork products are of higher likelihood of purchase preference.

EMPIRICAL ESTIMATION RESULTS AND DISCUSSION
This study uses binary logistic model to do the regression, and the results is shown in Table 6.The marginal effects coefficients of significant explanatory variables in model regression are calculated according to Equation (4).The estimated coefficient values of the model are shown in Table 7. Consumer's individual characteristics such as gender, age, marital status and education level have no significant effect on consumer's purchase preference for certified pork products.
As to the consumer's household feature variables, the monthly household income is the important factors Consumer's family scale has positive and significant influence on his purchase preference probability for certified pork products (significant at 5% level).One person increased in the household, consumer's actual purchase preference probability for certified pork products will raises 8.08%.Some previous researches considered that with the increase of family scale, the family economic burden may be much heavier which brought poorer purchase ability for the certified agricultural products.This conclusion is contrary to our research result.
The urban consumers having higher household income may be related with the faster work rhythm in Beijing.It would need the relatives or nannies to take care the families, as a result, the consumers who have higher household income and larger family scale, the purchase odds for certified pork products may be much higher too.The variables of whether or not the consumer's household having children under 18 years old and the elder over 60 years old have no positive impact on his purchase preference for certified pork products.
Consumers' knowledge about certified agricultural products has a positive effect on their purchase preference probability for certified pork products (at a significant level of 1%).The accurate judgments about the quality of the certified agricultural products will reduce the asymmetric information in the market and improve consumers' actual purchase behavior for these products.If consumer's knowledge about certified agricultural product increases one unit, his probability of the stable purchase preference will raise 8.68%.
Consumer's willingness-to-pay for the certified pork has positive effect on his purchase preference for certified pork products at 1% level of significance.The statistical results also indicate that the much higher willingness-topay for the certified pork, the higher probability of purchase these products will be.One unit increased in consumer's willingness-to-pay will make him add 20.18% odds to their actual purchase behavior.
Consumers' perception of the current safe-quality risks of pork market has a significant effect on their purchase preference for certified pork products at the level of 1%.
The consumers worry about the present safe-quality risks of the pork market and are concerned with the certified agricultural products, thus increasing their real purchase behavior for these products.Consumer's perception of safe-quality risks increases one unit which raises 18.65% probability to his actual purchase behavior for certified pork products.
Consumer's trust level in the quality of certified pork products has not showed the significant effect on his actual purchase behavior for certified pork, which indicates that although some consumers subjectively trust in certified pork products, they cannot hold stable purchase behaviors restricted by some economic and other factors.

CONCLUSIONS AND SUGGESTIONS
This paper analyzes the affecting factors of consumers' purchase preference for fresh certified pork products and the effect degree.It is found that, though pork product is the main livestock of urban residents in Beijing, the consumers still have lower buying ratio of certified pork products presently.Consumers have stated preference for these certified pork products, but only a few of them turn the potential purchase intention into actual purchase behavior.Those who have higher household income, higher willingness-to-pay for certified pork products, and perception of the current quality safety risks of pork market will be of higher probability of actual purchase behavior for certified pork products.The factors such as consumer's knowledge about certified agricultural product, family scale also have more significant impacts on the probability of the consumer's purchase preference for certified pork products.
The income limitation and higher price of safe food are still important factors that consumers purchasing preference for certified pork products in this study.We have found that the consumers have higher willingness-to-pay for lower-price certified pork products in markets generally.As the Beijing urban per capital income continues to increase at a very fast pace in the recent years, more people will join this new higher income class and will likely have higher willingness-to-pay for safe-quality food.
The reality of more circulation link and higher transaction costs boosts final retail price in Chinese agricultural market.Support policy in livestock industry should be taken into consideration in China.The economic measures of reducing all kind of costs in production and marketing processes of the certified pork products will help to lower the final price of the certified products gradually.In order to restrict small-size framer production, popularizing the combination of supermarket, production bases or the farmer association and individual farmer not only shorten the food supply chains, but also control the safe production.In good turn consumers trustworthiness and safe consumption should be strengthened.
Unlike in developed countries where it is mandated that the food ingredients be labeled which consumers have full right to know the food quality, China has not yet implemented such strict measures.The inefficient supervision restricts consumers' trust in the food safequality and governmental power at present.Food safety incidents often arise from problems of asymmetric information between consumers and producers of food with regards to product-specific attributes in China.
Establishing a strict food traceability system from farmer to consumer will reduce the asymmetric information and enhance Chinese consumers' trust and consumption level on the safety food.The effective publicity such as holding lectures, training consumers with safe-quality knowledge, media spread and advertising will decrease the information gap between market and they will enhance consumer's loyalty for certified products.
Although, Beijing urban consumers are in general concerned about food safety and have stated preference for certified pork products in market surveys, they are yet to have stable purchase preference.From the marketing point of view, the surveys from manufacturers and marketers of certified pork products should focus on those groups who have higher willingness -to-pay for certified products and higher income level, thus the target consuming groups should be chosen efficiently.
Consumer's willingness-to-pay for certified pork products Consumer's trust in the quality of certified pork products Attitude

Table 2 .
Assignment and descriptive statistics of the explanatory variables.

Table 3 .
The primary quality characteristics with consumers concern when they buying fresh pork products.

Table 4 .
Distribution of consumer's characters within purchase preference groups (%).

Table 5 .
Consumers' willingness -to-pay for certified pork products.

Table 6 .
Binary logistic model regression results.