the future of food demand understanding differences in global economic models understanding the capacity of agricultural systems to feed the world population under climate change requires projecting future food demand this article reviews demand modeling approaches from 10 global economic models participating in the agricultural model intercomparison and improvement project agmip we compare food demand projections in 2050 for various regions and agricultural products under harmonized scenarios of socioeconomic development climate change and bioenergy expansion in the reference scenario ssp2 food demand increases by 59 98 between 2005 and 2050 slightly higher than the most recent fao projection of 54 from 2005 2007 the range of results is large in particular for animal calories between 61 and 144 caused by differences in demand systems specifications and in income and price elasticities the results are more sensitive to socioeconomic assumptions than to climate change or bioenergy scenarios when considering a world with higher population and lower economic growth ssp3 consumption per capita drops on average by 9 for crops and 18 for livestock the maximum effect of climate change on calorie availability is 6 at the global level and the effect of biofuel production on calorie availability is even smaller

trying to explain home bias in equities and consumption investors hold a substantially larger proportion of their wealth portfolios in domestic assets than standard portfolio theory would suggest a phenomenon called equity home bias in the absence of this bias investors would optimally diversify domestic output risk using foreign equities therefore consumption growth rates would tend to co move across countries even when output growth rates do not empirically however consumption growth rates tend to have a lower correlation across countries than do output growth rates a phenomenon i call consumption home bias in this paper i discuss these two biases and their potential relationship as suggested by the literature

examining the heterogeneity in calorie income elasticities a meta analysis abstract several studies conducted over the past three decades on calorie income relationship appear to give inconclusive results this paper reviews these studies and employs meta regression analysis to examine the potential publication bias in the calorie income elasticity as well as the impact of specific study attributes on the elasticities that have been reported in the empirical literature a total of 40 empirical studies which yielded 99 estimated elasticities were considered the results indicate the presence of publication bias in the reported elasticities besides the estimates revealed evidence of positive and significant empirical effect of income on calorie intake from all the studies that goes beyond publication bias study attributes such as ranking of the journal panel data used in the analysis whether expenditure was used as proxy for income year of primary survey sample size and numbers of the years of primary data were found to have statistically significant impacts on the reported calorie income elasticities in the literature

changes in the structure of global food demand may 1998 purdue agec staff paper 98 5 a newly developed demand system is used to estimate the response of food and food product demand to per capita expenditure changes the resulting engel elasticities are then used to project food and food product demand in 2020 assuming per capita expenditure and population changes results suggest that while food expenditure is projected to grow it accounts for a smaller proportion of total expenditure further analysis indicates change in the composition of food demand away from a grain and towards livestock is projected to occur in lower income countries in 2020

economic growth convergence and world food demand and supply in projecting global food demand to 2050 much attention has been given to rising demand due to the projected population increase from the current 7 4 billion to more than 9 billion an increasingly important source of the increase in food demand is per capita demand growth induced by rising income per person since the proportion of income spending on food decreases as incomes rise growth in global food demand will be greater if incomes grow faster in developing countries than in high income countries such a pattern of income convergence has become established in recent years making it important to assess the implications for food demand and supply using a resource based measure of food that accounts for the much higher production costs associated with dietary upgrading this paper concludes that per capita demand growth is likely to be a more important driver of food demand than population growth between now and 2050 using the middle ground international institute for applied systems analysis shared socioeconomic pathway projections to 2050 which assume continued income convergence the paper finds that the increase in food demand 102 percent would be roughly a third greater than without convergence 78 percent since the impact of convergence on the supply side is much more muted convergence puts upward pressure on world food prices partially offsetting a baseline trend toward falling world food prices to 2050

how big are potential welfare gains from international risksharing abstract there is extensive evidence that risksharing across countries is far from perfect some have attributed this to small benefits from risksharing gains from riskpooling that have been reported range from negligible to enormous this paper documents to what extent the results are sensitive to the parameterization of preferences the stochastic process of the endowment and its measurement we find that gains from risksharing are quite sizable for realistic assumptions about the underlying factors for oecd countries they are equivalent to a permanent increase in tradables consumption in the range of 1 1 to 3 5 for a 50 year horizon and 2 5 to 7 4 for a 100 year horizon

systemic risk and international portfolio choice returns on international equities are characterized by jumps moreover these jumps tend to occur at the same time across countries leading to systemic risk we capture these stylized facts using a multivariate system ofjump diffusion processes where the arrival of jumps is simultaneous across assets we then determine an investor s optimal portfolio for this model of returns systemic risk has two effects one it reduces the gains from diversification and two it penalizes investors for holding levered positions we find that the loss resulting from diminished diversification is small while that from holding very highly levered positions is large returns on international equities are characterized by jumps 1 moreover these jumps tend to occur at the same time across countries implying that conditional correlations between international equity returns tend to be higher in periods of high market volatility or following large downside moves 2 our objective in

a system of demand equations satisfying effectively global regularity conditions a parametric specification of an indirect utility function in terms oaf expenditure and two unit cost functions is proposed specification of these unit cost functions in terms of regular functions leads to the notion of an effectively globally regular system of demand equations that is a system of demand equations that is regular over a cone in expenditure price space and for which the regular region includes all points in any given sample and all values of nominal expenditure and prices generating higher values of real expenditure than the sample minimum this general model nests a number of popular demand systems such as the linear expenditure system as special cases an empirical application illustrates some of these ideas copyright 1996 by mit press

a modified implicit directly additive demand system a recently developed demand system nicknamed aidads an implicit directly additive demand system offers an approach to capturing consumer preferences across a wide range of expenditure levels aidads generalizes the les by assuming marginal budget shares vary with utility and hence with expenditure like the les aidads includes subsistence parameters that define minimum consumption levels here we present a modified aidads maidads that replaces the constant subsistence parameters with functions that also vary with utility these transformed subsistence levels are referred to as minimum consumption quantities this model is applied to the 1996 international consumption project data as these data span a wide range of expenditure levels maidads offers a viable alternative for the estimation of a global demand system results suggest minimum consumption quantities for staple grains livestock other food products alcohol and tobacco clothing and footwear and transport and transport services vary

an implicitly additive demand system the problem of endowing large applied general equilibrium models with numerical values for parameters is formidable for example a complete set of own and cross price elasticities of demands for the monash model of the australianeconomy involves in excess of 50000 items invoking the minimal assumptions that demand is generated by utility maximization reduces the load to about 26000 obviously still a number much too large for unrestrained econometric estimation to obtain demand systems estimates for a dozen or so generic commodities at a top level of aggregation categories like food clothing and footwear etc typically johansen s lead has been followed and directly additive preferences imposed upon the underlying utility function with the move beyond one step linearized solutions of applied general equilibrium models the functional form of the demand system adopted becomes an issue the most celebrated of the additive preference demand systems the linear expenditure system les has one

loss aversion asymmetric market comovements and the home bias abstract loss aversion has been used to explain why a high equity premium might be consistent with plausible levels of risk aversion the intuition is that the first order different utility impact of wealth gains and losses leads loss averse investors to behave similarly to investors with high risk aversion but if so should those agents not perceive larger gains from international diversification than standard expected utility investors with plausible levels of risk aversion they might not because comovements in international stock markets are asymmetric correlations are higher in market downturns than in upturns this asymmetry dampens the gains from diversification relatively more for loss averse investors we analyze the portfolio problem of such an investor who has to choose between home and foreign equities in the presence of asymmetric comovement in returns perhaps surprisingly in the context of the home bias puzzle we find that loss averse investors behave similarly to those with standard expected utility preferences and plausible levels of risk aversion we argue that preference specifications that appear to perform well with respect to the equity premium puzzle should be subjected to this test

westernization of asian diets and the transformation of food systems implications for research and policy abstract rapid economic and income growth urbanization and globalization are leading to a dramatic shift of asian diets away from staples and increasingly towards livestock and dairy products vegetables and fruit and fats and oils while the diversification of diets away from the traditional dominance of rice with rising incomes is expected and observed current food consumption patterns are showing signs of convergence towards a western diet the diet transition is characterized by increased consumption of wheat temperate fruit and vegetables and high protein and energy dense food globalization and the consequent global interconnectedness of the urban middle class is the driving force behind the convergence of diets the rapid spread of global supermarket chains and fast food restaurants is reinforcing the above trends the growing demand for diet diversity cannot be met solely by the traditional food supply chain it requires the modernisation of the food retail sector and the vertical integration of the food supply chain in effect linking the consumers plate to the farmers plow as a consequence asian agriculture is on an irreversible path leading away from its traditional pre occupation with cereal crop production especially rice towards a production system that is becoming increasingly commercialized and diversified this paper describes the determinants and trends in the diversification and westernization of asian diets implications of the evolving demand trends for food supply and retail systems are presented the paper discusses the prospects for small farmer participation in the emerging food supply system with a particular emphasis on asian rice production systems finally the paper considers emerging challenges for food policy small holder welfare and agricultural research and development priorities

do prices and attributes explain international differences in food purchases food purchases differ substantially across countries we use detailed household level data from the united states france and the united kingdom to i document these differences ii estimate a demand system for food and nutrients and iii simulate counterfactual choices if households faced prices and nutritional characteristics from other countries we find that differences in prices and characteristics are important and can explain some difference e g united states france difference in caloric intake but generally cannot explain many of the compositional patterns by themselves instead it seems an interaction between the economic environment and differences in preferences is needed to explain cross country differences jel d12 i12 l11 l66 q11 food purchases differ across countries within countries over time and across demographic groups these differences seem to be correlated with rates of excess weight gain and diet related illness economists tend to attribute the difference in food purchases across markets to differences in prices an alternative explanation is that they are due to inherent differences in preferences and eating habits in this article we study the differences in food purchases and nutritional outcomes across countries focusing on the united states united kingdom and france we start by systematically documenting the differences in food purchases for consumption at home between the united states united kingdom and france we show that us households purchase different foods from french and uk households for example us households purchase more calories per person a greater percentage of those calories comes in the form of carbohydrates and a lower share in the form of proteins a higher share of expenditure is on drinks and prepared foods and

world food demand long term projections of global food demand are heavily dependent on which functional form of the food demand equation is used given that real incomes can change substantially over the long term key elements are the dependence of the income elasticity on income which ensures that the food budget share always lies within the 0 1 range and the role of income inequality this article analyzes these issues proposes a new functional form that deals with them and presents estimates of income and price elasticities for food in 138 countries copyright 2012 oxford university press

co managing common pool resources do formal rules have to be adapted to traditional ecological norms abstract we examine the effectiveness of three democratically chosen rules that alleviate the coordination and cooperation problems inherent in collectively managed common pool resources in particular we investigate how rule effectiveness and rule compliance depend on the prevailing local norms and ecological values held by resource users for this purpose we employ a framed field experiment that is based on a rangeland model for semi arid regions and carried out with communal farmers in namibia and south africa participants could vote for three best practice management rules found in many places around the world that are discussed for implementation in the study area temporary private property rights rotational grazing or limitation of livestock numbers all rules were designed in a way that facilitated cooperation or coordination of actions the focus of this study lies on the interactions between these rules and prevalent ecological norms exhibited in the rounds prior to rule implementation in contrast to previous lab experimental studies we find that democratic voting of rules is not sufficient for high rule compliance and an overall enhancement in cooperation rules turned out to be inefficient if they were in conflict with the prevalent ecological norm

the random utility hypothesis and inference in demand systems in this paper the authors examine the consequences of adopting the random utility hypothesis as an approach for randomizing a system of demand equations random utility models are appealing since they allow the usual assumption of deterministic utility maximizing behavior by each consumer to coexist with the apparent randomness across individuals that is exhibited by data their results show that the use of random utility models implies that the disturbances of the demand equations may not be homoskedastic but must be functions of prices and or income copyright 1989 by the econometric society

identifying supply and demand elasticities of agricultural commodities implications for the us ethanol mandate we present a new framework to identify supply elasticities of storable commodities where past shocks are used as exogenous price shifters in the agricultural context past yield shocks change inventory levels and futures prices of agricultural commodities we use our estimated elasticities to evaluate the impact of the 2009 renewable fuel standard on commodity prices quantities and food consumers surplus for the four basic staples corn rice soybeans and wheat prices increase 20 per cent if one third of commodities used to produce ethanol are recycled as feedstock with a positively skewed 95 percent confidence interval that ranges from 14 to 35 per cent jel q11 q16 q42 q48

estimating consumer demands across the development spectrum maximum likelihood estimates of an implicit direct additivity model abstract this paper characterizes consumer demand patterns across the development spectrum using elasticity estimates from a demand system possessing non linear engel effects demands for six broadly defined goods are then projected under the assumption that per capita expenditure growth rates differ across the development spectrum such projections illustrate the extent to which non linear income effects generate more plausible demand responses estimated marginal budget shares for food decline in a logistical manner and range from about 0 5 for ethiopia to less than 0 05 for the usa engel elasticities for food range from 0 95 for ethiopia to less than 0 1 for the usa

nutrition transition and the structure of global food demand estimating future demand for food is a critical aspect of global food security analyses the process linking dietary changes to wealth is known as the nutrition transition and presents well identified features that help to predict consumption changes in poor countries this study proposes to represent the nutrition transition with a nonhomothetic flexible in income demand system known as the modified implicitly directly additive demand system maidads the resulting model is transparent and estimated statistically based on cross sectional information from faostat it captures the main features of the nutrition transition rise in demand for calories associated with income growth diversification of diets away from starchy staples and a large increase in caloric demand for animal based products fats and sweeteners the estimated model is used to project food demand between 2010 and 2050 based on a set of plausible futures trend projections and shared socioeconomic pathways scenarios the main results of these projections are as follows 1 global food demand will increase by 46 less than half the growth in the previous four decades 2 this growth will be attributable mainly to lower middle income and low income countries 3 the structure of global food demand will change over the period with a 95 increase in demand for animal based calories and a much smaller 18 increase in demand for starchy staples and 4 the analysis of a range of population and income projections reveals important uncertainties depending on the scenario the projected increases in demand for animal based and vegetal based calories range from 78 to 109 and from 20 to 42 respectively

economic growth convergence and agricultural economics after nearly two centuries of lagging behind the industrial countries growth in many developing countries has surged since the early 1990s this outperformance has major implications for almost all areas of agricultural economics and if continued will likely do so into the future this article aims to identify the key ways in which the changes in rich and poor country growth rates matter for agricultural economists as a basis for formulating better research agendas a key impact arises through sharp increases in demand for agricultural resources as demand for livestock products increases this changing structure of food demand has important implications for nutrition studies and policies with the emergence of a double burden of malnutrition on the supply side growth in developing countries tends to increase domestic food supply which is also boosted by increases in research and development spending growth in developing countries both stimulates and benefits from increases in infrastructure investment evaluation of which requires new analytical tools negative impacts include the contribution of increased demand for livestock products to global greenhouse gas emissions in terms of trade policy growth in developing country is tending to lead to convergence of agricultural policies with the pattern of assistance seen in today s developed countries raising concerns about the future need to deal with collective action problems particularly those that increase the volatility of world prices