minimax regret and strategic uncertainty this paper introduces a new solution concept a minimax regret equilibrium which allows for the possibility that players are uncertain about the rationality and conjectures of their opponents we provide several applications of our concept in particular we consider pricesetting environments and show that optimal pricing policy follows a non degenerate distribution the induced price dispersion is consistent with experimental and empirical observations baye and morgan 2004

agriculture in the global economy agriculture is diverse and full of contradictions the sector accounts for a griculture is diverse and full of contradictions the sector accounts for a comparatively small share of the global economy but remains central comparatively small share of the global economy but remains central to the lives of a great many people in 2012 of the world s 7 1 billion to the lives of a great many people in 2012 of the world s 7 1 billion people an estimated 1 3 billion 19 percent were directly engaged in farming people an estimated 1 3 billion 19 percent were directly engaged in farming but agriculture including the relatively small hunting fi shing and forestry sectors but agriculture including the relatively small hunting fi shing and forestry sectors represented just 2 8 percent of overall income world bank 2012 however in represented just 2 8 percent of overall income world bank 2012 however in today s middle and low income countries where most of the world s farmers are today s middle and low income countries where most of the world s farmers are to be found agriculture accounts for a much greater share of national income and to be found agriculture accounts for a much greater share of national income and employment for instance in india agriculture represents 18 percent of national employment for instance in india agriculture represents 18 percent of national income and 54 percent of employment income and 54 percent of employment 1

abstraction tendencies and stylised facts a realist approach to economic analysis in his numerous methodological asides and assertions that feature in his more empirically oriented postwar contributions nicholas kaldor makes frequent reference to notions of abstraction tendencies and stylized facts however the employment of such terms seems rarely to be explicitly questioned justified or explicated this paper argues that such notions can be readily explicated and their employment justified through adopting an explicitly realist approach to economic analysis it is also argued that realism represents a serious alternative to current orthodox approaches to economics without suffering from some of the latter s more obvious limitations copyright 1989 by oxford university press

realism underlabouring and institutions despite recent advances economic methodology has found it difficult to transcend certain positivist premisses and concerns we argue that developments in philosophy and social theory under the heading of critical realism are particularly significant with respect to overcoming these problems to illustrate we focus upon various themes that arise in a recent collection concerned with economic methodology and institutionalist economics relating these themes to relevant aspects of this realist position in so doing we argue that an economic methodology restricted to description and an institutionalism committed to some form of methodological individualism are not only unnecessary but problematic

information and the hold up problem we examine situations in which a party must make a sunk investment prior to contracting with a second party to purchase an essential complementary input we study how the resulting hold up problem is affected by the seller s information about the investing party s likely returns from its investment our principal focus is on the effects of the investment s being observable by the non investing party contrary to popular intuition we find that an improvement in the seller s information e g the investment s being observable rather than not can benefit the buyer and harm the seller we also find that other popular intuitions about this problem are either false incomplete or require strong assumptions to be valid

the unknown masterpiece marx s model of capital this paper develops an alternative to traditional interpretations of karl marx rooted in his 1859 preface widely regarded as the definitive summary of his materialist conception of society it does this by reading marx in the light of the ontology of realism and the reproductive mode of inference via an examination of some pivotal texts centered around the grundrisse notebooks the paper indicates how a realist understanding of marx s reproductive method can be used to reconstruct and develop its creation marx s model of capital copyright 1998 by oxford university press

information design in the holdup problem we analyze a bilateral trade model where the buyer chooses the distribution of her valuation for the good the seller after observing the buyer s distribution but not the realized valuation makes a take it or leave it offer if distributions are costless the price and the payoffs of both the buyer and the seller are shown to be 1 e in the unique equilibrium outcome the buyer s equilibrium distribution generates a unit elastic demand and trade is ex post efficient these properties are shown to be preserved even when different distributions are differentially costly as long as the cost is monotone in the dispersion of the distribution

procurement and renegotiation parties bound by an incomplete contract have an incentive to renegotiate after acquiring new information the issue of the parties investment in the relationship before renegotiation is analyzed in a simple two period procurement model the firm invests in the first period it then learns its production cost and the sponsor learns its value for the project williamson s underinvestment presumption is shown to hold under very general assumptions about bargaining and about the ex post asymmetry of information as long as the firm s investment is not observable by the sponsor the introduction of a cancellation fee may well lead to even less investment contrary to what is sometimes argued the role of ex ante price fixing as an alternative way to reintroduce some form of commitment and the problem of cost overruns are discussed last it is shown that if investment is observable by the sponsor andthus may become a joint decision variable the two parties may choose to under or overinvest

can openness mitigate the effects of weather shocks evidence from india s famine era transformation of countries throughout history rural citizens in developing countries today however remain highly exposed to fluctua tions in the weather this exposure affects the incomes these citizens earn and the prices of the foods they eat recent work has documented the significant mortality stress that rural house holds face in times of adverse weather robin burgess olivier deschenes dave donaldson and michael greenstone 2009 masayuki kudamatsu torsten persson and david stromberg 2009 famines times of acutely low nominal agricultural income and acutely high food prices are an extreme manifestation of this mapping from weather to death lilian c a knowles 1924 describes these events as agricultural lockouts where both food sup plies and agricultural employment on which the bulk of the rural population depends plummet the result is catastrophic with widespread hun ger and loss of life though now confined to the world s poor est countries food shortages and famines were features of most preindustrial societies over time there has been intense debate over what role openness to trade in food might play in

empirical studies on agricultural impacts and adaptation abstract agricultural production is heavily dependent on weather outcomes and hence climate change has the potential to significantly alter the sector s productivity both reduced form studies as well as integrated assessment models have found that the agricultural sector might experience significant impacts we discuss the advantages of empirical reduced form studies and their link and potential usefulness to integrated assessment models we further discuss challenges facing empirical studies and recent research that looks at the longer term changes in climate and attempts to measure adaptation

evolving comparative advantage and the impact of climate change in agricultural markets evidence from 1 7 million fields around the world a large agronomic literature models the implications of climate change for a variety of crops and locations around the world the goal of the present paper is to quantify the macro level consequences of these micro level shocks using an extremely rich micro level data set that contains information about the productivity both before and after climate change of each of 10 crops for each of 1 7 million fields covering the surface of the earth we find that the impact of climate change on these agricultural markets would amount to a 0 26 percent reduction in global gdp when trade and production patterns are allowed to adjust since the value of output in our 10 crops is equal to 1 8 percent of world gdp this corresponds to about one sixth of total crop value

should african rural development strategies depend on smallholder farms an exploration of the inverse productivity hypothesis in africa most development strategies include efforts to improve the productivity of staple crops grown on smallholder farms an underlying premise is that small farms are productive in the african context and that smallholders do not forgo economies of scale a premise supported by the often observed phenomenon that staple cereal yields decline as the scale of production increases this paper explores a research design conundrum that encourages researchers who study the relationship between productivity and scale to use surveys with a narrow geographic reach when policy would be better served with studies based on wide and heterogeneous settings using a model of endogenous technology choice the authors explore the relationship between maize yields and scale using alternative data since rich descriptions of the decision environments that farmers face are needed to identify the applied technologies that generate the data improvements in the location specificity of the data should reduce the likelihood of identification errors and biased estimates however the analysis finds that the inverse productivity hypothesis holds up well across a broad platform of data despite obvious shortcomings with some components it also finds surprising consistency in the estimated scale elasticities

united states demand for food and nutrition in the twentieth century the relationships between diet and health are once again the center of debate over farm and food policy targeted food aid programsfood stamps aid to families with dependent children and the women infants and children program can create incentives for food purchases and consumption that are not consistent with those created by programs to support farm prices and incomes marketing orders target prices and deficiency payments the sugar program and farm price supports the result could be that food aid recipients spend more on food but are presented with incentives to eat unhealthy diets due to policy induced price distortions understanding the economic forces behind food and nutrient con

changes in sectoral composition associated with economic growth in this paper the author uses dynamic general equilibrium methods to examine the interrelationship between sectoral composition and growth she shows that growth is affected by sectoral composition and vice versa the model is basically a solow model of sustained growth with multiple consumption goods and nonhomothetic preferences each consumption good is produced using different factor intensities the rate of exogenous technological change is different in each sector nonhomotheticity of preferences drives the result that sectoral composition affects growth rates copyright 1997 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the determinants of subsistence income in a malthusian world abstract this study constructs a simple two sector malthusian model with agriculture and industry and uses it to identify the determinants of income in a malthusian equilibrium we make standard assumptions about preferences and technologies but in contrast to existing studies we assume that children and other consumption goods are gross substitutes consistent with the conventional malthusian model the present theory shows that productivity growth in agriculture has no effect on equilibrium income more importantly we also show that equilibrium income varies not just with the death rate as has recently been demonstrated in the literature but also with the level of productivity in the industrial sector an empirical analysis using data for pre industrial england lends support to both hypotheses

information and bargaining in the hold up problem this article incorporates an information structure with partial information into the canonical hold up problem the optimal information structure balances the tradeoff between ex ante efficiency the information rent effect and ex post efficiency the bargaining disagreement effect with one shot bargaining it occurs at an intermediate level of information asymmetry when there is repeated bargaining it is attained with perfect asymmetry asymmetric information the parameter that is frequently ignored in the literature turns out to be an important welfare instrument for the hold up problem our results therefore provide a basis for institutional design regarding the optimal control of information flow

pricing without priors we consider the problem of pricing a single object when the seller has only minimal information about the true valuation of the buyer specifically the seller only knows the support of the possible valuations and has no further distributional information the seller is solving this choice problem under uncertainty by minimizing her regret the pricing policy hedges against uncertainty by randomizing over a range of prices the support of the pricing policy is bounded away from zero buyers with low valuations cannot generate substantial regret and are priced out of the market we generalize the pricing policy without priors to encompass many buyers and many qualities

preventives versus treatments preventives are sold ex ante before disease status is realized while treatments are sold ex post even if the mean of the ex ante distribution of consumer values is the same as that ex post the shape of the distributions may differ generating a difference between the surplus each product can extract if for example consumers differ only in ex ante disease risk then a monopolist would have more difficulty extracting surplus with a preventive than with a treatment because treatment consumers having contracted the disease no longer differ in disease risk we show that the ratio of preventive to treatment producer surplus can be arbitrarily small in particular when the distribution of consumer values has a zipf shape and the disease is rare the firm s bias toward treatments can be reversed for example if the source of private information is disease severity learned ex post the difference between the producer surplus earned from the products can result in distorted rd the deadweight loss from this distortion can be as large as the entire producer surplus difference calibrations for hiv and heart attacks based on risk factors in the u s population suggest that the distribution of disease risk is sufficiently zipf similar to generate substantial differences between producer surplus from preventives and treatments empirically we find that proxies for the zipf similarity of the disease risk distribution are associated a significantly lower likelihood of vaccine development but not drug development jel codes o31 l11 i18 d42

global economic growth and agricultural land conversion under uncertain productivity improvements in agriculture we study how stochasticity in the evolution of agricultural productivity interacts with economic and population growth at the global level we use a two sector schumpeterian model of growth in which a manufacturing sector produces the traditional consumption good and an agricultural sector produces food to sustain contemporaneous population agriculture demands land as an input itself treated as a scarce form of capital in our model both population and sectoral technological progress are endogenously determined and key technological parameters of the model are structurally estimated using 1960 2010 data on world gdp population cropland and technological progress introducing random shocks to the evolution of total factor productivity in agriculture we show that uncertainty optimally requires more land to be converted into agricultural use as a hedge against production shortages and that it significantly affects both optimal consumption and population trajectories

induced bias of technical change in agriculture the united states and japan 1880 1980 because of extreme differences in factor endowments and price ratios among factors between the united states and japan both countries have experienced sharply different patterns of factor use and productivity growth in agriculture for the past 100 years of modern economic growth in this study the method of testing the hicksian hypothesis of induced innovation was developed using the two level ces production function the model was applied to the historical data of u s and japanese agricultural development for 1880 1980 the results were consistent with the hypothesis that different patterns of technical change in the two countries were induced by differences in the levels and the movements in relative factor prices

selling labor low wage responses to productivity shocks in developing countries productivity risk is pervasive in underdeveloped countries this paper highlights a way in which underdevelopment exacerbates productivity risk productivity shocks cause larger changes in the wage when workers are poorer less able to migrate and more credit constrained because of such workers inelastic labor supply this equilibrium wage effect hurts workers in contrast it acts as insurance for landowners agricultural wage data for 257 districts in india for 1956 87 are used to test the predictions with rainfall as an instrument for agricultural productivity in districts with fewer banks or higher migration costs the wage is much more responsive to fluctuations in productivity

the demand for food and calories we investigate nutrition and expenditure in rural maharashtra in india we estimate that the elasticity of calorie consumption with respect to total expenditure is 0 3 0 5 a range that is in accord with conventional wisdom the elasticity declines only slowly with levels of living and is far from the value of zero suggested by a recent revisionist literature in these indian data the calories necessary for a day s activity cost less than 5 percent of the daily wage which makes it implausible that income is constrained by nutrition rather than the other way around

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

complements versus substitutes and trends in fertility choice in dynastic models demographers emphasize decreased mortality and economic development as the main contributors generating the demographic transition contrary to previous findings we show that simple dynastic models a la barro becker can reproduce observed changes in fertility in response to decreased mortality and increased productivity growth if the intertemporal elasticity of substitution is low enough we show that this is largely due to number and welfare of children being substitutes in the utility of parents in this case we find that with an ies of one third model predictions of changes in fertility amount to two thirds of those observed in u s data since 1800 between 1800 and 2000 fertility choice in the united states underwent a dramatic transition depending on estimates it fell from about six children per woman to around two children per woman this demographic transition from a state of high fertility and high mortality to low fertility and low mortality has been documented by demographers and historians in the united states and in every other developed country in the world over this same period natural rates of population growth net of immigration also fell but less substantially demographers have not reached a consensus on the root causes of this transformation but list several changes as likely main contributors these include reductions in infant and child mortality rates imrs and cmrs and the process of industrialization and economic development the work in demography and history on this topic has largely been limited to empirical studies with almost no choice based modeling of the type seen in economics even there issues of the timing of changes