Food security in Kenya: Insights from a household food demand model

This paper evaluates the household food security situation in Kenya in terms of access to food. We apply a quadratic almost ideal demand system (QUAIDS) model to nationally representative household survey data from Kenya, and estimate and interpret price and expenditure elasticities as indicators of household sensitivity to market shocks. Our estimation results show positive expenditure elasticities, close to unity, while all compensated and uncompensated own-price elasticities are negative and smaller in magnitude. A complementary welfare analysis shows high compensated variations in the long run, ranging between 34% and 131% across food groups. This suggests that rising relative food costs have led to deterioration of the food security situation in Kenya, and the most severely affected households seem to be those that rely on informal markets and reside in rural areas. To improve food security, targeted income support could be a more effective policy than price support, given the much higher estimated expenditure elasticities.     

The US retail demand for fish products: an application of the almost ideal demand system

The main objective is to address the limitations of past US fish demand research through the development of a variation of the almost ideal demand system model for disaggregate fish products at the retail level. Price and expenditure elasticities, as well as elasticities of substitution between fish products and other protein commodities, determined from this work may be used in the context of fisheries management and market development and promotion. Results indicate that with the exception of shellfish, demand for the various fish products is relatively inelastic. Cross-price elasticities are generally moderate while expenditure elasticities are large and positive for fresh fish and shellfish. Demographic effects, especially geographical division, season, race, occupation, age–sex household composition, and price–income interaction, as a proxy for quality, are highly significant variables.     

Household food demand in rural China

This article explores rural household food consumption behaviour in China using a large household data set from Jilin Province. Data are classified into four main food groups—grain, vegetable products, animal products and other foods. A household food demand system, incorporating four household characteristics, is estimated using an LA-AIDS model, assuming a three-stage budgeting procedure. Expenditure elasticities for a range of food groups are estimated, with a particular focus on animal products. The inclusion of household characteristics did not have a big impact on the elasticity values in any of the three stages of the budgeting process. The total expenditure elasticity for grain (Stage II) was 0.64, suggesting substantial future growth in household demand for fine grains such as rice and wheat, as per capita incomes continue to grow in rural areas. The highest conditional and total expenditure elasticity values were for the animal products (Stage II) group, 1.22 and 0.76, respectively. Within this group the elasticities were highest for the meat sub-group at 1.14 and 0.87, respectively, suggesting an almost proportionate increase in demand as household incomes grow. Added demand pressures from animal production will likely keep grain policy high on the political agenda.     

Quantile Regression Analysis of Predictors of Calorie Demand in India: An Implication for Sustainable Development Goals

This study examined predictors of households’ calorie demand using consumer expenditure survey data during the time frame of millennium development goals. It draws suggestions for achieving sustainable development goals to eliminate calorie-poverty. We used the log of per-capita calorie intake as the calorie demand. Endogeneity corrected quantile regression was applied to examine the distributional effect of predictors. Findings revealed calorie-monthly per-capita consumption expenditure (MPCE) elasticities were positively statistically significant across quantiles in rural-and urban-areas, but, contrary to traditional wisdom, elasticities are lower for calorie-poor than calorie-rich households. Dietary diversification of food items, relative food price, and share of medical-and education-expenditure were the main adverse drivers of calorie demand. Our results are robust to the under-reporting and measurement error. The policy implications are: (a) only focusing on pro-poor income enhancing strategies will not able to reduce calorie deprivation, it should be backed by imparting awareness about food choice and nutritional value of low price food items, (b) to implement necessary policy to maintain stable food inflation and effectively targeted food subsidy for calorie poor, (c) to adopt forward-looking medical-and education-policy such as free health and education facilities to all by enhancing public spending to revive the quality of public hospitals and educational institutions.

     

City size and household food consumption: demand elasticities in Spain

Are food price elasticities different across city sizes? The aim of this article is to estimate expenditure and own-price elasticities for 10 aggregated food product groups using the Spanish Household Budget Survey for the year 2010. These products are the ones for which the survey provides information regarding prices and quantities, thus allowing the application of an Almost Ideal Demand System (AIDS) model with censored data. The estimation procedure allows not only comparisons to be made among households with different levels of income, but also the contribution of residence characteristics to variations in demand. The results confirm that the size of the city in which the household resides has a similar significant and relevant effect on consumption patterns as family income level. This is especially clear with own-price elasticities. In Spain, large central cities show a greater response to price changes than smaller cities or rural peripheral areas.     

Household demand for fats and oils: two-step estimation of a censored demand system

A censored system of household fat and oil demand equations is estimated with a two-step procedure, using cross-sectional data from the 1987–1988 US Nationwide Food Consumption Survey. Own price and total expenditure elasticities are close to unity and there is no evidence of gross substitutability. Compensated elasticities suggest net substitution among the products considered.     

Food expenditures and household demographic composition in the US: a demand systems approach

Food expenditures and subsistence quantities of poverty status and non–poverty status US households are analysed within a Linear Expenditure System that postulates subsistence quantities to be linear combinations of demographic variables. Using the US Bureau of Labor Statistics' 1992 Consumer Expenditure Survey and Detailed Monthly Consumer Price Indices, this article obtains expenditure elasticities, own–price elasticities and subsistence quantities for each income group across nine broadly aggregated food commodity groups. Elasticity estimates and subsistence quantity estimates differ across income groups, supporting the premise that policies targeted at specific income groups should be based on the target group's elasticity estimates rather than average population elasticities. Parameter estimates are then used to simulate how subsistence quantities and own–price elasticities can be expected to vary according to the demographic composition of the household within a specific income group.     

Estimating demand elasticities under rationing

Eliminating rationing in the United Kingdom following the Second World War was a concern for policy-makers because of potentially large fluctuations in post-war prices and the impact on unrationed goods. This study shows that in using virtual prices, elasticities can be estimated from a ‘free’ demand system consistent with observed consumer choices. Substitution estimates without accounting for rationing are misleading. In contrast, using virtual prices and estimating a ‘free’ market system yield results similar to those of the pre-war period. Results show that food rationing affected expenditure across unrationed goods. Rationing on other services had little effect on expenditure across unrationed goods.     

The effects of price on household demand for food and calories in poor countries: are our databases giving reliable estimates?

Food price policy relies heavily on estimated price elasticities of food demand to help balance the nutritional and economic objectives in poor countries. Economists use either unit values (ratios of household expenditure to quantity purchased) or community prices (enumerated from vendors in local markets) as proxies for market prices when estimating price elasticities with household survey data. Biases are believed to result from using unit values, due to measurement error and quality effects, but evidence on this issue is lacking and even less is known about community prices. This article provides an empirical evidence from Vietnam, which suggests that economists should exercise caution when estimating price elasticities from household surveys. A 14-food demand system is estimated alternatively with unit values or community prices, and the elasticity of calories with respect to rice prices is calculated. This elasticity is more than twice as large (?0.54 versus ?0.22) when community prices are used rather than unit values. Hence, conclusions about the nutritional effects of rice price increases appear sensitive to data choices made by economists. More generally, this discrepancy suggests that the household survey databases commonly used by economists may not provide reliable estimates.     

Kalman filter and the demand for cigarettes

kalman filter estimates of price, income and advertising elasticities are presented. An analysis of structural change in the demand for cigarettes in the US for the period 1929–86 is made. Estimated price and income elasticities are generally smaller, and the advertising elasticity larger, than estimates previously found. Cigarette demand is inelastic with respect to price and income, and advertising elasticity is statistically insignificant for the most part. Furthermore, both income and price elasticities decline over time while advertising elasticity tends to rise. Four time periods where structural change has occurred are identified. The health scare reports and the Fairness Doctrine Act have a significant impact on per capita cigarette consumption.     

The household demand for energy and fuels in OECD countries

This paper estimates the household demand for energy and fuels. The linear expenditure model is estimated using data from eight OECD countries over a period of sixteen years. The basic similarities in household demand for fuels and the differences among OECD countries are discussed. The results indicate that household demand for energy is highly income dependent. With regard to four basic fuels, the income and price elasticities for gasoline and gas are higher than for either coal or oil. The demand patterns are shown to differ significantly among groups of OECD countries. Coal has been gradually replaced by oil as the major household fuel in OECD countries, whereas the demand pattern for gas has changed only a little during the fifties and sixties.     

Income and price elasticities of demand at low levels of real income

For levels of real per capita income starting at 3% of the U.S. per capita income in 1975, income and price elasticities of demand are tabulated. The prominent role of food consumption for low-income households is emphasized.     

International comparisons of expenditure patterns

The linear expenditure system (LES) of Stone (1954) is fitted to an eight-commodity classification of personal consumption expenditures in the national accounts data of 19 countries widely dispersed in the development spectrum. Cross-country comparison of the results reveals some discernible patterns in the variations of price and expenditure elasticities as a function of GNP per head. In particular, Food's own-price and expenditure elasticities are estimated to decline in absolute value as real GNP per head increases. Overall, own-price elasticities and cross-price elasticities with respect to food appear to account for about 80% of total price responsiveness in the fitted system.     

Carbon mitigation costs for the commercial building sector: Discrete–continuous choice analysis of multifuel energy demand

We estimate a carbon mitigation cost curve for the U.S. commercial sector based on econometric estimation of the responsiveness of fuel demand and equipment choices to energy price changes. The model econometrically estimates fuel demand conditional on fuel choice, which is characterized by a multinomial logit model. Separate estimation of end uses (e.g., heating, cooking) using the U.S. Commercial Buildings Energy Consumption Survey allows for exceptionally detailed estimation of price responsiveness disaggregated by end use and fuel type. We then construct aggregate long-run elasticities, by fuel type, through a series of simulations; own-price elasticities range from −0.9 for district heat services to −2.9 for fuel oil. The simulations form the basis of a marginal cost curve for carbon mitigation, which suggests that a price of $20 per ton of carbon would result in an 8% reduction in commercial carbon emissions, and a price of $100 per ton would result in a 28% reduction.     

Elasticity estimates of farmed salmon demand in Spain and Italy

In this paper, estimates of the elasticities that characterize the structure of demand for farmed salmon in Spain and Italy are reported. The demand models are specified using a Box-Cox transformation of the variables and a Hausman test is used to determine price endogeneity in the demand equations. The results show short-run unitary own-price elasticity of demand for farmed salmon in both markets, but long run estimates show significant elastic price response. Short run substitution of salmon for other fish species is not observed and, for both Spain and Italy, farmed salmon is characterized as a luxury good. Interestingly, we show that our a priori expectations about own-price elasticities being lower in smaller market areas is confirmed. Finally, the results obtained are compared to other recent results reported in the salmon demand literature.     

Invariance, price indices and estimation in almost ideal demand systems

Two issues are addressed in this paper. First, we explore the issue of price index invariance in the linearized Almost Ideal demand system. We establish that the Stone index, which lacks invariance, and the recently proposed invariant Laspeyres, Paasche and Tornqvist indices all generate biased and inconsistent estimators. Monte Carlo evidence shows that invariance does not necessarily lead to better estimates of price and income elasticities insofar as the Stone and Paasche indices are unambiguously inferior to the Laspeyres and Tornqvist indices, especially if prices are not strongly positively correlated. Second, we examine the merits of the widely used conditional ML estimator of the non-linear Almost Ideal system in which a prior value is chosen for the “subsistence” parameter. We find that the bias and trace mean square error increases induced by conditional estimation are modest. The choice between the linearized and the non-linear models favors the latter although in some cases linear methods are as good as non-linear. First Version Received: January 1999 / Final Version Received: March 2000     

The demand for imports: Estimates of bilateral trade flows

This paper provides estimates, using a traditional import demand model, of the demand for imports on a bilateral basis among nine industrialized nations. These estimates provide greater detail about price and income elasticities, but in general are consistent with earlier, aggregate import demand studies with respect to conclusions about the effects of secular and cyclical income changes on trade balances and whether sufficiently high price elasticities are present to insure that the Marshall-Lerner stability condition is met.     

The supply and demand for imports and exports in a simultaneous model

Previous studies on the behaviour of aggregate exports and imports have tended to ignore the simultaneous relationship between quantity and price. This paper investigates the price responsiveness of export and import demand and supply in eight African countries. The results indicate that export demand price elasticities are smaller when the sample is African. The import supply and demand elasticities were found to be generally large. The Marshall–Lerner condition of balance of payment stability is found to be easily satisfied. A positively sloped function of export supply is found to exist for a majority of countries in the sample. The average time lag of export supply is found to be about a year. The disequilibrium model is found to be more appropriate for import demand, import supply and export supply.     

Consumer behaviour in India: An application of the Rotterdam demand system

The purpose of this paper is to analyse the extent to which the observed data support the postulates of neoclassical theory of consumer behaviour. The absolute price version of the Rotterdam model has been estimated for rural and urban areas of India separately. The results indicate a trade off between theoretical consistency and goodness of fit. The symmetry, but not homogeneity, conditions are found to be empirically valid in rural India. All the other hypotheses are rejected both in rural and urban areas of India. Frequent violation of convexity conditions is also observed. The estimated marginal budget shares, income and price elasticities show marked differences in consumption patterns of rural and urban consumers in India. The effect of foodgrains price rise on the demand for various items is also analysed.     

Meat and fish consumption patterns in Saudi Arabia

This study analyses the demand for meat (beef, chicken and lamb) and fish in Saudi Arabia in a system-wide framework using data for the period 1985–2010. A preliminary data analysis reveals that, in Saudi Arabia, the relative consumption of beef, chicken and fish has a positive growth, while lamb has a negative growth. The average relative price growth rates of beef, chicken and fish are negative, while that of lamb is positive. The expenditure shares of beef, chicken and fish have increased while that of lamb has fallen. The estimation results of the demand system reveal that there is an autonomous trend out of lamb into beef, chicken and fish. The implied income elasticities indicate that beef, lamb and fish are considered to be luxuries, while chicken is a necessity. The demand for all meat products and fish are price inelastic. These elasticities are key inputs for policy analysts in terms of devising policies in relation to meat production, meat imports, taxation and food security issues in Saudi Arabia. The usefulness of the implied elasticities is demonstrated by simulating the consumption of beef, chicken, lamb and fish under various policy scenarios.