An Empirical Assessment of Endogeneity Issues in Demand Analysis for Differentiated Products

This article explores the issue of price and expenditure endogeneity in empirical demand analysis. The analysis focuses on the U.S. carbonated soft drink market. We test the null hypothesis that price and expenditures are exogenous in the demand for carbonated soft drinks. Using an almost ideal demand system (AIDS) specification, we strongly reject exogeneity for both prices and expenditures. We find that accounting for price/expenditures endogeneity significantly impacts demand elasticity estimates. We also evaluate the implications of endogeneity issues for testing weak separability.     

Quantifying the structure of food demand in China: An econometric approach

This article examines food demand structure and its dynamics for 11 commodities in urban China. The analysis is based on household‐level expenditure survey data for two cross‐sectional surveys of Chinese households pertaining to food expenditure patterns during 1995 and 2003. Pre‐committed components of commodity demands, that are insensitive to economic variables, are explored. We use the generalized quadratic almost ideal demand system (GQAIDS) for its empirical superiority to the generalized almost ideal demand system (GAIDS), and estimate the associated parameters via full information maximum likelihood procedure (FIML) accounting for endogeneity of total expenditures on food for home consumption (FAH). We also use quality‐adjusted commodity unit values to control for quality differences resulting from commodity aggregation and food choice. Furthermore, we derive GQAIDS elasticity formulas, and estimate income elasticities without restrictions. The results partially support the hypothesis that an average Chinese household has incorporated elements of Western diet (fine grains) into traditional Chinese food diet over time. Moreover, the outcome of a simple test developed here points to possible preference changes for a majority of food staples under study.     

Food Import Demand in the Czech Republic

This paper provides an overview of Czech food import demand in the transition period of the 1990s. It provides econometric estimates of own‐ and cross‐price elasticities as well as group expenditure elasticities of Czech import demand for sixteen lower level and four upper level food groups. Based on the Hausman test for endogeneity, which supported the hypothesis that Czech import prices were exogenously determined outside of the Czech economy, we estimated five demand models as direct‐demand systems of the AIDS type. The econometric estimation of elasticities used bimonthly data from March 1993 to August 1997.     

Markets and welfare effects of food fraud

This study develops a theoretical framework of heterogeneous consumers and producers and imperfectly competitive food companies to analyse the system‐wide market and welfare effects of food fraud in the form of food adulteration and mislabelling. The results show that, while the price impacts of food fraud are product‐specific with the equilibrium prices of high‐quality and low‐quality products moving in different directions, the equilibrium quantities depend on the relative magnitude of the demand and supply effects of food fraud. Regarding the welfare effects of food fraud, they are shown to be highly asymmetric across different consumers and producers. In addition to enabling the disaggregation of the welfare effects of food fraud, the explicit consideration of agent heterogeneity, asymmetries in the probability of fraud detection and the endogeneity of the producer quality choices also enables the derivation of a key result of this study; contrary to what is traditionally believed, both low‐quality and high‐quality producers can have economic incentives to commit fraud. The group that is more likely to cheat is determined by the social attitudes towards fraudulent behaviour, the enforcement policy parameters and the relative magnitude of the demand and supply effects of food fraud. A comparison of the market effects of mislabelling and food adulteration reveals that, while the equilibrium quantity of the high‐quality product is higher in the presence of mislabelling, producers are more likely to mislabel than adulterate their products.     

Demand for meat and dairy products by Turkish households: a Bayesian censored system approach

We extend the Tobit (censored) linear equation system procedure to utility‐theoretic demand functions, along with a mapping mechanism to impose the adding‐up restriction implied by consumer utility maximization theory—a theoretical restriction very often ignored in previous empirical studies with censored demand systems. In this context, the Bayesian Markov Chain Monte Carlo (MCMC) procedure is applied to the censored linear approximate almost ideal demand system (LAIDS) for 12 food products, using data from the Turkish Household Expenditure Survey. All own‐price elasticities are negative and expenditure elasticities positive. Uncompensated own‐price elasticities for rural households are generally much higher than those for their urban peers, though demand for most food products are own‐price elastic for both types of households. The differential patterns in demand elasticities between urban and rural households become even more evident (almost twice) as relatively more expensive foodstuffs are consumed, showing that accessibilities to alternative products have made rural Turkish households more cognizant toward price changes in foods. Household characteristics play a key role in food expenditures, notably so in urban areas, and regional and seasonal differences are also present.     

Demand for animal‐derived food in selected Asian countries: A system‐wide analysis

Food consumption patterns in Asia show a trend away from staples toward high protein food derived from animal and dairy products, fruit and vegetables, fats and oils. Such changes in food consumption patterns are due to rising incomes, urbanization, globalization, and modernization of marketing infrastructure. In this article, we analyze the demand for the animal‐derived food group comprising meat (chicken, beef, pork, and mutton), eggs and fish, and derive income and price elasticities in seven Asian countries using the system‐wide approach. Demand homogeneity and Slutsky symmetry properties were tested and found to be compatible with the data. Our findings reveal that animal‐derived food as a group is a necessity (except in Taiwan) and its demand is price inelastic (except in Taiwan and Sri Lanka). The implied unconditional demand elasticities reveal that, in all countries (except beef in Japan and Taiwan), chicken, beef, pork, mutton, eggs and fish (except in Taiwan) are all necessities and the demand for all types of animal‐derived food in all seven countries are mostly price inelastic. The cross‐price elasticity estimates are mostly found to be positive, meaning that there is a higher degree of substitutability between chicken, beef, pork, mutton, eggs, and fish.     

Food demand elasticities for Australia

There is renewed interest in robust estimates of food demand elasticities at a disaggregated level not only to analyse the impact of changing food preferences on the agricultural sector, but also to establish the likely impact of pricing incentives on households. Using data drawn from two national Household Expenditure Surveys covering the periods 1998/1999 and 2003/2004, and adopting an Almost Ideal Demand System approach that addresses the zero observations problem, this paper estimates a food demand system for 15 food categories for Australia. The categories cover the standard food items that Australian households demand routinely. Own‐price, cross‐price and expenditure elasticity estimates of the Marshallian and Hicksian types have been derived for all categories. The parameter estimates obtained in this study represent the first integrated set of food demand elasticities based on a highly disaggregated food demand system for Australia, and all accord with economic intuition.     

Food Demand in Russia: Heterogeneous Consumer Segments over Time

The Russian food system has undergone substantial changes. However, knowledge on how economic transition has affected the structural parameters of food demand is lacking. Based on a two‐stage LES‐LA/AIDS model and annual panel data from the Russia Longitudinal Monitoring Survey (1995–2010), we provide a comprehensive set of food demand elasticities for Russia along two dimensions. First, we estimate demand parameters for three characteristic time periods in order to trace changes during transition. Second, to account for the Russian population's diversity, we derive elasticities for five different consumer segments. These groups are established by a cluster analysis based on households' food purchases. Our findings suggest that demand for food is far from satiated in Russia. We find generally high unconditional expenditure and own‐price elasticities for food. Both expenditure and own‐price elasticities show slight decreases in absolute terms over time. Low expenditure elasticities for staple foods like bread or cereals and high values for luxury goods such as meat, alcohol and tobacco suggest considerable changes in the composition of food baskets with further income growth. Results indicate that food production at home loses in importance while more affluent households in particular increase their demand for food consumption away from home.     

How to Understand High Food Prices

Agricultural price booms are better explained by common factors than by market‐specific factors such as supply shocks. A capital asset pricing model‐type model shows why one should expect this and Granger causality analysis establishes the role of demand growth, monetary expansion and exchange rate movements in explaining price movements over the period since 1971. The demand for grains and oilseeds as biofuel feedstocks has been cited as the main cause of the price rise, but there is little direct evidence for this contention. Instead, index‐based investment in agricultural futures markets is seen as the major channel through which macroeconomic and monetary factors generated the 2007–2008 food price rises.     

The Demand for Food Quality in Rural China

Many studies of food demand do not use actual prices but unit values, obtained by dividing expenditures by the quantity consumed. This can bias empirical analyses because unit values are not exogenous market prices; they reflect household food quality choices within each food category. This article develops a framework for assessing the resulting bias in income and price elasticities of demand and applies the framework to data for rural China. Empirical results indicate that households in rural China tend to consume higher-quality food as income increases, with a greater sensitivity to income for basic foods than for luxury foods.     

Demand for milk quantity and safety in urban China: evidence from Beijing and Harbin

Urban households account for most of the milk consumption in China, but their consumption is hampered by safety concerns. Using survey data collected in Beijing and Harbin in 2010, this paper simultaneously analyses urban households' milk consumption using a multiple linear model and their willingness‐to‐pay for milk safety using an ordered choice model. The results of this study show that as income increases, urban households consume more milk and are willing to pay a higher premium for milk safety. Modern food marketing channels play a positive role in stimulating milk consumption and building consumers' confidence in milk safety. The growth in the elderly population influences milk consumption positively, but their demand for milk safety is negatively affected by higher price. The combined analysis of households' demand for milk quantity and safety may be useful to the Chinese government in promoting the development of the domestic milk industry and to dairy firms in exploring the milk market in China.     

An econometric analysis of demand for food quantity and quality in urban China

This article offers an analytical framework for studying consumer demand for food quality based on a theory‐consistent demand model, namely, the Exact Affine Stone Index specification. Importantly, it accounts for unobserved consumer and regional heterogeneity, and allows for arbitrary Engel curves. The empirical value of our framework is illustrated in an econometric analysis of demand for food quality in China. Evaluating possible structural changes in consumer food expenditures in China is of paramount importance, given the ever‐increasing global role of China and the implications of the structural food preference changes for the global food system. The major findings emerging from this study indicate that income is an important determinant of demand for food quality and quantity with the relatively more affluent provinces having a higher affinity for food quality.     

Lithuania's food demand during economic transition

The linear approximate version of the almost ideal demand system (LA‐AIDS) model is estimated using data from the Lithuanian household budget survey (HBS) covering the period from July 1992 to December 1994. Price and real expenditure elasticities for 12 food groups were estimated based on the estimated coefficients of the model. Very little or nothing is known about the demand parameters of Lithuania and other former socialist countries, so the results are of intrinsic interest. Estimated expenditure elasticities were positive and statistically significant for all food groups, while all own‐price elasticities were negative and statistically significant, except for that of eggs which was insignificant. Results suggest that Lithuanian household consumption did respond to price and real income changes during their transition to a market‐oriented economy.     

Price and quantity endogeneity in demand analysis: evidence from directed acyclic graphs

We propose to use the emerging method of directed graphs to study price/quantity endogeneity issues in empirical demand analysis. The approach is illustrated through the examination of U.S. meat consumption. We find that for two major meat products (beef and poultry), retail prices contemporaneously caused quantities consumed, thus were predetermined. In contrast, the quantity consumed of pork appeared to be predetermined relative to its price.     

The effects of China's growth on the food prices and the food exports of other developing countries

This article explores the impacts of China's growth in the international markets of agricultural products along two dimensions: food price inflation and export growth in other developing countries. China's food imports of vegetable oils have grown dramatically over the last decade, linking China's economic growth to the recent increases in global food prices. If China is a source of global food price inflation, exporting countries will benefit whether they sell directly to China or not. These direct and indirect linkages are explored using a short‐run, partial‐equilibrium model of international trade in agricultural products in which consumer prices and trade costs are derived from bilateral trade flows. China's effects on food prices and exports are estimated by reducing Chinese food expenditures in 2007 by half, roughly China's level of expenditures in 1995. Results indicate that food prices as measured by CES price indexes in developing Asia, Africa, and Latin America would have been reduced by 1.27%, 0.32%, and 0.22%, respectively. China has been an important source of growth for exporters selling directly to China. There is no evidence of export growth due to an overall increase in food prices caused by China's growth.     

Measuring Market Power for Food Retail Activities: French Evidence

In this paper we develop and estimate an empirical model of pricing behaviour for food retail firms in both a quantity‐setting oligopoly engaged in the joint production of demand‐related final goods and a quantity‐setting oligopsony for supply‐unrelated wholesale goods. The procedure consists of estimating an inverse demand system for the final goods, single supply functions for the wholesale goods and the retail industry first‐order profit‐maximisation conditions, from which an estimate of the degree of imperfect competition and of oligopoly‐oligopsony power for the different commodities can be retrieved. The model is applied to the French food retail industry and three commodities are distinguished: dairy products, meat products and other food products. We strongly reject the hypothesis that French food retail firms behave competitively, and more than 20 and 17 per cent of the wholesale‐to‐retail price margins for dairy products and meat products, respectively, can be attributed to oligopoly‐oligopsony distortions.     

Estimating food demand in Paraguay from household survey data

We estimate a food demand system in Paraguay based on the 1997 national household survey, considering 12 food categories. To obtain demand elasticity estimates from household survey data accounting for quality effects, measurement errors, and censored observations, price indexes are obtained from ordinary least squares predictions of changes in unitary values caused by spatial and temporal variations, and the two‐step estimation procedure ( Shonkwiler and Yen, 1999 ) is applied. Our approach yields reasonable estimates of combined quantity and quality responses with respect to price. Results suggest distinct consumption behavior in urban and rural areas, particularly for chicken, eggs, dairy, and fats and oils, which are likely because of differences in the food distribution system and availability of nonmarket food sources.     

Regime Shifts in the Fish Meal/Soybean Meal Price Ratio

Aquaculture growth has led to worries about overfishing and reduction in wild‐caught food fish supply because of increased demand for fish meal. As such, the price ratio between fish meal and soybean meal has received much attention as an indicator of changing market conditions. In recent years, the price ratio between these two commodities has become more volatile. Several authors have suggested that the traditional relationship between fish meal and soybean meal has broken down and that this is evidence of increased demand pressure on fish meal. In this article, we investigate the hypothesis that there are two regimes for the relative price between fish meal and soybean meal. The empirical results support this hypothesis, with the low‐price regime representing the traditional stable relative price. The continued linkages between the fish meal and the soybean meal markets indicate that aquaculture is reducing its dependency on marine proteins in favour of vegetable proteins.     

On estimating Armington elasticities for Japan's meat imports

By fully accounting for the distinct tariff regimes levied on imported meat, we estimate substitution elasticities of Japan's two-stage import aggregation functions for beef, chicken and pork. Although the regression analysis crucially depends on the price that consumers face, the post-tariff price of imported meat depends not only on ad valorem duties but also on tariff rate quotas and gate price system regimes. The effective tariff rate is consequently evaluated by utilising monthly transaction data. To address potential endogeneity problems, we apply exchange rates that we believe to be independent of the demand shocks for imported meat. The panel nature of the data allows us to retrieve the first-stage aggregates via time dummy variables, free of demand shocks, to be used as part of the explanatory variable and as an instrument in the second-stage regression.     

Economies of Scale and the Demand for Food in Switzerland: Parametric and Non‐Parametric Analysis

This paper examines the role of household public goods arising from co‐residence and economies of scale in the allocation of household expenditure. Using both parametric and non‐parametric methods, the paper tests the theoretical prediction that in the presence of shared public goods, larger households should have higher per capita consumption of private goods like food, provided that they do not substitute too much towards the effectively cheaper public good. The results indicate that, at constant per capita total expenditure, the per capita demand for food declines with household size. No evidence is found in favour of the hypothesis that the endogeneity of male and female hours of work in the labour force could be responsible for this anomaly. However, an examination of the role of direct economies of scale in explaining this negative relationship yielded a negative relationship between household size and quality adjusted unit values, suggesting that the effects of direct economies of scale dominate those generated by public goods.