assessing the effects of tariff reform on u s food manufacturing industries the role of imperfect competition and intermediate inputs recent work indicates that the joint effects of intermediate input and final output tariff reforms on equilibrium in the differentiated final products sector are analytically ambiguous this issue is addressed empirically for disaggregate imperfectly competitive u s food manufacturing industries the input tariff effect dominates in most industries leading to increases in the number of u s firms and total industry output as a result of tariff reform this provides evidence that the existing u s tariff profile discriminates against domestic food manufacturers as input tariff effects outweigh the protection offered by output tariffs this conclusion is robust to changes in the degree of interfirm rivalry monopolistic competition or cournot oligopoly

aggregation and pairwise aggregation of demand when the distribution of income is fixed abstract this paper derives necessary and sufficient conditions for pairwise aggregation of the demand functions of a group of consumers conditions under which the mean demand for each pair of consumers satisfies the slutsky restrictions when the distribution of income is fixed the sufficient conditions imply existence of a representative competitive consumer whose demand is the mean demand of the group the necessary conditions imply that such a representative consumer exists for every fixed income distribution only if the consumers have homothetic preferences or alternatively if for each price vector all the consumers income expansion paths lie in the same plane

national price levels purchasing power parity and cointegration a test of four high inflation economies abstract the time series properties of exchange rates and wholesale prices from four high inflation countries show some evidence in support of purchasing power parity tests for stationarity of real exchange rates and cointegration among price and exchange rate variables are presented for argentina brazil chile and israel during the 1970s and 1980s error correction models describe the mechanism of adjustment to long run equilibrium

trade in technology a potential solution to the food security challenges of the 21st century abstract the recent rise in caloric undernutrition in sub saharan africa ssa demonstrates the continued relevance of the malthusian footrace between food availability and population sluggish growth in farm productivity in ssa has brought to the fore the key role of agricultural technology in alleviating future food insecurity we develop a model of technology food security and international trade with three distinct channels for technology reduce food insecurity in ssa the first is via greater domestic r d investment an alternative is to import technologies from other countries with significant knowledge capital the third role for technology to resolve the malthusian dilemma in ssa is that of virtual technology trade i e importing technological investments undertaken elsewhere through cheaper imported food to assess the relative contribution of each channel to food security in africa we employ a partial equilibrium quantitative trade model augmented by a temporal relationship between r d investments knowledge capital and agricultural productivity over the historical period 1991 2011 we find that direct r d investments in ssa have been the dominant vehicle for lowering food prices in africa looking forward to 2050 we find that virtual technology trade will be the most important vehicle for reducing non farm undernutrition in africa

discrete choice cannot generate demand that is additively separable in own price abstract we show that in a unit demand discrete choice framework with at least three goods demand cannot be additively separable in own price this result sharpens the analogous result of jaffe and weyl 2010 in the case of linear demand and has implications for testing of the discrete choice assumption out of sample prediction and welfare analysis

sophisticated entry in a model of spatial competition we analyze free entry equilibrium in a model of spatial competition in which locations of established firms are fixed and entrants profit expectations are rational our most interesting results concern large economies economies in which the number of firms is arbitrarily large when the average cost function is u shaped free entry equilibrium is unique socially optimal and characterized by zero profit in contract when there are no diseconomies of scale even large economies are stubbornly imperfect firms can earn substantial pure profit and free entry equilibrium is neither unique nor socially optimal

the neoclassical trojan horse of steady state economics the vision of a steady state economy elaborated by herman daly describes an economy that uses materials and energy within the regenerative and assimilative limits of the planet s ecosystems sustainable scale just distribution and efficient allocation are its constitutive theoretical goals this paper is a critique of the theoretical foundations of steady state economics it argues that steady state economics consists in an attempt to squeeze neoclassical economics into a biophysical and ethical corset as a result many fundamental flaws and criticisms of neoclassical economics remain as a consequence steady state economics does not lead to a radical departure from or improvement upon neoclassical theory but rather to fundamental internal inconsistencies between the old economics paradigm and new progressive ecological economic thinking contradictions appear at various levels ranging from ontology and methodology to theory and values as daly has pioneered the foundations of ecological economics with his thinking these ambiguities are not only problematic for steady state economics but ecological economics as a field more generally the paper concludes that ecological economics has to let go of neoclassical foundations as they contradict its core values and ambitions a new and consistent theory of political economy of the environment along heterodox lines is needed

mix and match a strategyproof mechanism for multi hospital kidney exchange as kidney exchange programs are growing manipulation by hospitals becomes more of an issue assuming that hospitals wish to maximize the number of their own patients who receive a kidney they may have an incentive to withhold some of their incompatible donor patient pairs and match them internally thus harming social welfare we study mechanisms for two way exchanges that are strategyproof i e make it a dominant strategy for hospitals to report all their incompatible pairs we establish lower bounds on the welfare loss of strategyproof mechanisms both deterministic and randomized and propose a randomized mechanism that guarantees at least half of the maximum social welfare in the worst case simulations using realistic distributions for blood types and other parameters suggest that in practice our mechanism performs much closer to optimal

location models as models of product choice abstract markets in which firm choice of product is an economic decision are commonly analyzed using a variant of the location model pioneered by hotelling econ j 39 1929 41 57 this paper develops a framework for formalizing the idea that a set of consumers with preferences defined over an abstract set of commodities can be represented as if they behaved as is typically assumed in the goods as locations models with this framework in place we are able to derive the preference assumptions underlying the two most common versions of these models and also to uncover the foundations of the now well known principle of minimum differentiation

a time series analysis of representative agent models of consumption andleisure choice under uncertainty this paper investigates empirically a model of aggregate consumption and leisure decisions in which utility from goods and leisure is nontime separable the nonseparability of preferences accommodates intertemporal substitution or complementarity of leisure and thereby affects the comovements in aggregate compensation and hours worked these cross relations are examined empirically using postwar monthly u s data on quantities real wages and the real return on the one month treasury bill the estimated values of the parameters governing preferences differ significantly from the values assumed in several studies of real business models several possible explanations of these discrepancies are discussed

the existence of input and output aggregates in aggregate production functions in this paper we make two contributions to the literature on aggregating inputs and outputs in economy production functions first we present necessary and sufficient conditions for aggregating efficiently allocated goods under general assumptions on the technology second we present a general theorem on the conditions for the existence of aggregates of both efficiently allocated goods and arbitrarily allocated goods we use this theorem to elucidate the role of efficiency in determining the existence of aggregates

two crises inflationary inertia and credibility this paper provides a comparative analysis of the mexican currency crisis of 1994 and the chilean crisis of 1982 to assess to what extent exchange rate based stabilisation programmes are successful in reducing or even eliminating inflationary inertia the paper provides a brief overview of the chilean and mexican reform and stabilisation programmes a theoretical model that emphasises the role of credibility is developed to analyse the effects of exchange rate based stabilisation programmes on inflationary inertia according to the model less than credible stabilisations will not eliminate inertia and will generate major real exchange rate overvaluation detailed data are used to test the hypothesis

aggregation in a model of price competition abstract in a model of price competition single product firms compete for consumers consumers purchase a variable quantity of one of the differentiated goods the paper provides results on equilibrium existence when consumers are heterogeneous in their evaluation of the differentiated goods among each other their evaluation of the differentiated goods relative to the outside good and heterogeneous in income furthermore i provide sufficient conditions for dominance solvability and monotone comparative statics journal of economic literature classification numbers d43 d11

efficiency and voluntary implementation in markets with repeated pairwise bargaining we examine a simple bargaining setting where heterogeneous buyers and sellers are repeatedly matched with each other we begin by characterizing efficiency in such a dynamic setting and discuss how it differs from efficiency in a centralized static setting we then study the allocations which can result in equilibrium when the matched buyers and sellers bargain through some extensive game form we take an implementation approach characterizing the possible allocation rules which result as the extensive game form is varied we are particularly concerned with the impact of making trade voluntary imposing individual rationality on and off the equilibrium path no buyer or seller consummates an agreement which leaves them worse off than the discounted expected value of their future rematching in the market finally we compare and contrast the efficient allocations with those that could ever arise as the equilibria of some voluntary negotiation procedure

the intrinsic limits of modern economic theory the emperor has no clothes assumptions of the uniqueness and stability of general equilibrium in a walrasian framework have no theoretical justification this paper argues that the key reason for this is that the walrasian model treats people as acting independently of one another especially in their demand behavior this independence plays an essential role in constructing economies with arbitrary excess demand functions thus making individual behavior dependent or similar may open the way to obtaining meaningful restrictions on aggregate excess demand functions copyright 1989 by royal economic society

estimating dynamic localization economies the inadvertent success of the specialization index and the location quotient estimating dynamic localization economies the inadvertent success of the specialization index and the location quotient regional studies after addressing definitional issues on the concepts of c

adjustment and social costs in chile during the 1980s abstract traditional analysis of adjustment programs tends to underestimate the welfare costs because it assumes that a contraction of nontradable production will close the expenditure income gap while the resulting excess supply of tradables will automatically be exported in chile however tradable output contracted sharply falling almost two thirds as much as nontradable output the conventional analysis also ignores the effect of adjustment on unemployment rates and on real wages this paper argues that the adjustment measures of the 1980s were regressive even though the government was successful in targeting its expenditures toward the very poor during the period of fiscal retrenchment among the regressive adjustment measures were the subsidies to holders of dollar denominated debt provided by the central bank in addition policies to reduce expenditures raised the unemployment rate over 26 reduced real wages by 20 for almost five years and reduced health housing and education budgets by 20 per capita finally the required real devaluation raised the cost of living for the poor

inward looking policies institutions autocrats and economic growth in latin america an empirical exploration this paper explores the institutionaldeterminants of economic growth in latinamerica by taking advantage of recentempirical research that employs subjectiveand objective measures to test for apossible northian explanation that linksinstitutional quality and economic growth we explore a simple framework that may helpbetter understand the policymakers choicesand persistence regarding inward lookingpolicies that were pursued between the1930s and the 1980s by arguing that in thelatin american case olson s 1982 idea ofencompassing interest should be expanded tocover not only the economic stakes of powerholders but in particular their psychicincome which includes their politicalstakes along the lines of recent work byrobinson 1997 coyne 2002 andothers

exports and labor demand searching for functional structure in multi output multi skill technologies to simplify the representation of a technological relationship between inputs and outputs a production unit s technology must typically satisfy some restrictive conditions some of them being well known in the literature this article presents new results for aggregating labor inputs and outputs in terms of restrictions on elasticities of scale and substitution these conditions are then empirically investigated in a framework that is flexible and does not lose its flexibility after separability being imposed the empirical findings of the exact approach to aggregation are found to be rather pessimistic on the possibility of providing a simplified representation

a representative consumer theory of the logit model the log it model is usually derived from a discrete choice approach with stoc hastic utilities it is shown here that the logit demand system may also be derived from the maximization of a deterministic entropy type utility the latter may be interpreted as the preference function of a representative consumer with variety seeking behavior this altern ative view suggests a generalization of the standard logit which allo ws total demand to be determined endogenously copyright 1988 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

a dynamic school choice model this paper inspires from a real life assignment problem faced by the mexican ministry of public education we introduce a dynamic school choice problem that consists in assigning positions to overlapping generations of teachers from one period to another teachers can either retain their current positions or choose a preferred one in this framework a solution concept that conciliates the fairness criteria with the individual rationality condition is introduced it is then proved that a solution always exists and that it can be reached by a modified version of the deferred acceptance algorithm of gale and shapley we also show that the mechanism is dynamically strategy proof and respects improvements whenever the set of orders is lexicographic by tenure

monopolistic competiton on the pyramid the purpose of this paper is to develop a model of monopolistic competition that has a simple locational interpretation and which allows for multifirm competition one of the major weaknesses of the standard circular road model is the fact that it allows only localized competition this creates problems when one wishes to analyze problems of international trade where one often has to work with firms with different production costs one of the major advantages of the pyramid model presented here is that one can easily compute the firms equilibrium profits even when their production costs differ copyright 1991 by blackwell publishing ltd

behavioral heterogeneity and the income effect inspired by the recent literature on aggregation theory this paper introduces hits a semiparametric model of consumer demand that allows for diversity in tastes the strong variation of budget shares observed across income groups has two possible origins the individual income effect and taste differences between poor and rich households consumer surveys reporting repeated cross sections do not permit the direct measurement of these two effects in hits linear heterogeneity allows the gmm estimation of structural coefficients on an aggregate series the joint density of spending and tastes is then recovered from cross sections by a nonparametric procedure involving a deconvolution we estimate the model on british data 1968 1998 and report that taste heterogeneity explains a large fraction of the variation of budget shares with income

aggregate structural macroeconomic analysis a reconsideration and defence aggregate structural macroeconomic analysis asma is frequently criticised for being ad hoc and justified if at all only as a pragmatic expedient this paper argues instead that asma is consistent with the principles of well established bodies of social theory appeal to these principles reveals that asma is adequate and likely even necessary for the successful prosecution of macroeconomic inquiry

full scale real tests of consumer behavior using experimental data abstract this paper reports on the results of three experiments based on the neoclassical theory of consumer behavior all these experiments were carried out with the aim of simulating real world behavior nonparametric tests applying the theory of revealed preference show that a significant number of individuals exhibit inconsistent behavior if nearly optimizing behavior is postulated then most of these inconsistencies disappear but random choices produce almost the same results the hypothesis of a representative consumer statistical average behavior seems a more fruitful approach

equilibrium with product differentiation tive consumer formulations is used to examine the properties of single and multiple price equilibria conditions under which decreases in the intensity of consumer preferences reduce price are given it is shown that with certain types of demand curves entry can eliminate price cost markups even given product differentiation if competition is localized it is demonstrated that entry does not affect the markup finally the effect of spurious product differentiation on price is examined

the bayesian foundations of solution concepts of games abstract we transform a noncooperative game into a bayesian decision problem for each player where the uncertainty faced by a player is the strategy choices of the other players the priors of other players on the choice of other players the priors over priors and so on we provide a complete characterization between the extent of knowledge about the rationality of players and their ability to successively eliminate strategies which are not best responses this paper therefore provides the informational foundations of iteratively undominated strategies and rationalizable strategic behavior b d bernheim econometrica 52 1984 1007 1028 d pearce econometrica 52 1984 1029 1050 sufficient conditions are also found for nash equilibrium behavior and a result akin to r j aumann econometrica 55 1987 1 18 on correlated equilibria is derived with different hypotheses

financial crises and balance of payments crises a simple model of the southern cone experience abstract this paper starts from a simple model of the domestic banking sector and develops the potentially destabilizing macroeconomic consequences of its role in intermediating foreign capital inflows both financial and balance of payments crises may result reminiscent of the southern cone experience

limited information and advertising in the u s personal computer industry traditional discrete choice models assume buyers are aware of all products for sale in markets where products change rapidly the full information assumption is untenable i present a discrete choice model of limited consumer information where advertising influences the set of products from which consumers choose to purchase i apply the model to the u s personal computer market where top firms spend over 2 billion annually on advertising i find estimated markups of 19 over production costs where top firms advertise more than average and earn higher than average markups high markups are explained to a large extent by informational asymmetries across consumers where full information models predict markups of one fourth the magnitude i find that estimated product demand curves are biased toward being too elastic under traditional models i show how to use data on media exposure to improve estimated price elasticities in the absence of micro ad data

house allocation with existing tenants an equivalence abstract we analyze two mechanisms designed to eliminate inefficiencies in house allocation problems where there are both existing tenants and newcomers the first mechanism chooses the unique core allocation of a sister exchange economy constructed by endowing each existing tenant with her current house and each newcomer with a random vacant house the second mechanism chooses an ordering from a given distribution and determines the final outcome as follows assign the agents the best available house one at a time following their ordering in the queue and whenever an agent demands the house of an existing tenant who is still in the line modify the queue by inserting the existing tenant at the top whenever a loop of existing tenants forms assign each of them the house she demands and proceed we show that the first mechanism is equivalent to an extreme case of the second which favors the newcomers

macroeconometric modeling and the theory of the representative agent the lucas critique of econometric policy evaluation 1976 argues that to the extent econometric models do not capture the primitive parameters of tastes and technology their coefficients can be expected to vary with changes in policy regimes several econometricians have undertaken empirical work that separates the parameters of tastes technology and policy estimating models that are in principle immune from this critique exemplary contributors to this effort have been thomas sargent 1978 and sargent and lars hansen 1980 the empirical work inspired by the lucas critique has proceeded using representative agent models and aggregate data the treatment of expectations and dynamic optimization has been careful although at times necessarily limited by the analytical requirements of attaining closed form solutions for dynamic programming problems under uncertainty potential problems due to aggregation have usually been ignored although when preferences and technology are quadratic it appears that they can be disposed of quickly assuming a representative firm is only a convenience as the model admits a tidy theory of aggregation sargent 1978 p 1016 it is ironic that a paradigm that emphasizes the isolation of the primitive parameters of tastes and technology has led to empirical work that has ben conducted almost exclusively with aggregate data there are exceptions t macurdy 1983 j biddle 1984 there are several difficulties with this development first the fact that representative agent models with exact aggregation can be constructed is unrelated to whether or not these models are adequate we can also construct models in which agents behavior is unaffected by the policy regime to exclusively model and test one but not the other appears to be a misplacement of emphasis second some of this work has proceeded using representative agents whose behavior cannot be aggregated exactly see m eichenbaum hansen and kenneth singleton 1984 for an example there is a third and most fundamental objection to empirical work which seeks to avoid the lucas critique yet uses aggregate data whenever econometric policy evaluation is undertaken using models estimated with aggregate data it is implicitly presumed that the aggregator function is structural with respect to the policy intervention in question formally aggregator functions are no more structural than are within regime reducedform relations of endogenous to policy variables as a modeling strategy ignoring the sensitivity of aggregators to policy changes seems no more compelling than ignoring the dependence of expectations on the policy regime this paper describes a very modest econometric model in which the effects of ignoring aggregation and of ignoring expectations each within the context of several representative agent models can be appreciated objective functions are quadratic and prices are disparate across agents in these respects the model s assumptions are in the mainstream of lucas and subsequent empirical work the model is carefully contrived so that exact aggregation is always possible this is not essential to the argument in any way but it drastically reduces the number of circumstances to be examined in constructing numerical examples the example pertains to neoclassical production and in each case there are three distinct representative agents one for production one for factor demand professor of economics duke university durham nc 27706 financial support from nsf grant ses8318778 and a sloan research fellowship are gratefully acknowledged a more detailed version of this paper is available on request from the author

transformations of the commodity space behavioral heterogeneity and the aggregation problem aggregation in exchange markets is studied by imposing restrictions on distributions of the households characteristics approximate bounds for market demand price elasticities that depend upon specific measures of behavioral heterogeneity are provided increasing behavioral heterogeneity makes aggregate expenditures more independent of prices this has strong consequences for the prevalence in the aggregate of the weak axiom of revealed preference of gross substitutability and on uniqueness and stability of the walrasian exchange equilibrium these strong macroeconomic regularities are obtained essentially through distributional assumptions as no rationality requirements are imposed on individual demand functions other than homogeneity and walras law journal of economic literature classification numbers d11 d41 d50 el 1992 academic press lnc there are still quite a few unpleasant gaps nowadays between macroanalysis and microanalysis of socioeconomic systems a leading instance drawn from social choice theory is arrow s celebrated impossibility theorem 1 which states that any attempt to aggregate individual preferences into a consistent social ordering or a collective choice procedure satisfying a few appealing requirements is bound to fail the impossibility arises however only if one insists that the procedure should work for every possible environment or in other words for all distributions of individual preferences a possible resolution of the problem is therefore to identify broad classes of distributions of preferences for which aggrega the bulk of the research reported in this paper was essentially done at yale university during the fall semester of 1990 i thank all my colleagues for their support and comments especially martin shubik herbert scarf and truman bewley i also had very useful conversations with jorgen weibull mike jerison andreu mas colell christian gouri6roux camille bronsard guy laroque bruno jullien and bernard caillaud i am much indebted to ai klevorick for his comments on an earlier draft but my greatest debt is to werner hildenbrand whose pioneering insights and stubborn insistance have over the years kept quite a few of us struggling beyond the fads of the moment with the aggregation problem our profession is fortunate indeed to have him around

valuing the characteristics of natural gas vehicles an implicit markets approach this paper estimates the costs of a government mandate to use natural gas vehicles focusing on the less desirable attributes that these vehicles 9 possess a model of producer and consumer behavior in a market for a differentiated product is constructed a hedonic price function is estimated and consumer surplus losses from the substitution of natural gas cars for gasoline cars are calculated these losses are found to be significant the average per car consumer surplus loss ranges from 1100 to 3200 with 20 to nearly 50 of the loss due to changes in vehicle characteristics the costs of such a policy appear to be greater than the environmental benefits but may not be too far out of line with the costs of alternative approaches for reducing vehicular pollution copyright 1996 by mit press

pricing strategies in a dynamic duopoly a differential game model we formulate a differential game model for dynamic pricing in a duopolistic market firms demand functions are derived from utility maximizing behavior of consumers with the demand for a brand given by the logit model preferences for brands are assumed to evolve over time in the market in a manner akin to learning models postulated in the marketing literature we derive the differential equations governing the equilibrium open loop price paths over time and show that in steady state the brand with the higher preference level charges the higher price the formulation is extended to include the effects of consumer heterogeneity and equilibrium steady state prices are compared with those obtained when heterogeneity is ignored a comparison of steady state dynamic prices with myopic prices is provided an empirical example is discussed to show how steady state model predictions may be obtained from actual longitudinal purchase data

monopolistic competition and preference diversity approach our model is especially attractive because it starts from economic primitives a specification of the set of possible individual preference patterns it shows how specific properties of the distribution of preferences translate into properties of aggregate demand this allows us to understand the relationship between the distribution of preferences and the degree to which the market introduces biases in product selection this paper presents a general model of the demand for differentiated products which has as special cases two of the most popular approaches used to analyse welfare and competition in monopolistically competitive markets the model of spatial competition on the circle and the model of symmetric aggregate demand the circle model is attractive because both demand and costs have a definite and easy to visualize physical foundation and because it is tractable salop 1979 provides an exemplary modem analysis with this model one can analyze the relationship between the optimal amount of product variety and the amount which a monopolistically competitive market will support in many plausible cases competition produces too much variety such a strong conclusion raises questions of robustness almost simultaneously spence 1976 and dixit and stiglitz 1977 developed an alternative approach to monopolistic competition based upon the chamberlinian assumption of symmetry see also shubik 1959 rather than specifying a distribution of preferences and deriving demand through aggregation as did salop and his predecessors these authors started by specifying a symmetric aggregate benefit function indicating how social welfare depends on the amounts of the various products supplied both spence and dixit stiglitz were able to show that the welfare conclusions from the circle model were not robust depending on the functional form of the benefit function equilibrium may entail either excessive or insufficient product variety 1 the assumption of symmetric demand has proven fruitful in the analysis of many economic problems it is therefore natural to ask what distribution of tastes would give

measuring product diversity abstract the diversity of a set of products can be defined as a function of the bilateral distances between its elements we show how these bilateral distances can be represented by parameters in a utility function and measured from observable data

the role of online platforms for media markets two dimensional spatial competition in a two sided market abstract we analyze the market for online and offline media in a model of two dimensional spatial competition where media outlets sell content and advertising space consumer preferences are distributed along the style and type of news coverage where the distance costs may vary across dimensions for integrated provision of online and offline platforms we show that entering the online market reduces average profits and may even constitute a prisoner s dilemma specialized provision may yield polarization in the style and type dimensions this is in contrast to the maximum minimum differentiation result previously established in the literature on multidimensional horizontal competition we show that maximal differentiation in both dimensions occurs due to the discrete nature of the type dimension and asymmetric advertising markets

strategyproof assignment by hierarchical exchange we give a characterization of the set of group strategyproof pareto optimal and reallocation proof allocation rules for the assignment problem where individuals are assigned at most one indivisible object without any medium of exchange although there are no property rights in the model the rules satisfying the above criteria imitate a trading procedure with individual endowments in which individuals exchange objects from their hierarchically determined endowment sets in an iterative manner in particular these assignment rules generalize gale s top trading cycle procedure the classical rule for the model in which each individual owns an indivisible good

strategic market coverage in spatial competition abstract we consider in this paper competition through prices and market coverages in a spatial duopoly we characterize and compare the stackelberg equilibria and the bertrand equilibria we show that when the cost of informing the consumers is small duopolists always choose to inform all consumers in the bertrand equilibrium but the leader in the stackelberg equilibrium may choose not to inform everyone when the duopolistic competition is intense enough thereby generating overlapping markets in equilibrium prices may be strategic complements strategic substitutes or be strategically independent considering market coverage as chosen by the firms changes the conventional relationships between differentiation profits and markups

engel curves leading to the weak axiom in the aggregate for every range of admissible incomes the authors characterize the class of engel curves with the property that if an economy has first a price independent distribution of income and second preferences which are identical across consumers and generate engel curves in the class then the corresponding aggregate demand function satisfies the weak axiom of revealed preference this class is defined by two simple conditions the no torsion condition says that in the relevant range of income the engel curve is contained in a plane through the origin the uniform curvature condition says that in addition the engel curve is either convex or concave to the origin copyright 1987 by the econometric society

the implications of additive community preferences in a multi consumer economy we investigate the consequences of imposing additivity on community preferences we show that there are important implications of additive community preferences that are not implied by the additivity of a single consumer s preferences in particular we show that imposing additivity on community preferences implies the existence of a representative consumer with a utility function in the ces family we demonstrate the restrictive nature of these implications with three examples our interpretation of the results is that single consumer models are unable to adequately represent important features of multi consumer economies

banks and macroeconomic disturbances under predetermined exchange rates abstract as the recent mexican crisis vividly illustrates latin american countries often go through boom bust cycles caused by both domestic policies and external shocks such cycles are typically magnified by weak banking systems which intermediate large capital inflows this paper develops a simple optimizing model to analyze how the banking sector affects the propagation of shocks in particular we show how the world business cycle and shocks to the banking system affect output and employment through fluctuations in bank credit we also analyze the countercyclical use of reserve requirements econometric evidence for chile and mexico supports the main predictions of the model

behind methodological individualism methodological individualism has become a more fashionable slogan for economistsin recent years in specific terms we are being urged to accept a doctrine within whichall explanations of social phenomena have to be couched in terms of statements aboutindividuals however the term has a wide and sometimes ambiguous usage and is beingemployed as a packaging for all kinds of methodological and theoretical prescriptions forexample it has been regarded as a commandment that thou shalt where possible placemacroeconomic statements on firm microeconomic foundations e g blaug 1980 or aninjunction against reckless aggregation particularly in regard to welfare criteria orsocial welfare functions e g kirzner 1980 littlechild 1978 or as an inspiration forrecent theoretical developments in economics with pro market policy conclusions e g furubotn and pejovich 1974 one of the further problems in discussing this topic is that often the term methodo logical individualism carries an ideological charge indeed by both advocates and itsopponents it is too frequently confused with individualism of a political variety however the connection between political and methodological individualism is merely assumed bythese supporters or critics or supported by cursory argument it is never demonstratedwith any rigour although there is a lack of uniformity in the use of the label it is argued here that the keyelement in the classic statements of methodological individualism is a refusal to examinethe institutional or other forces which are involved in the moulding of individual pref erences and purposes we are thus confronted with a remarkable optimism about thepossibility of explanation of social phenomena in terms of individuals but an extremereluctance to give even partial explanations of individual behaviour in social or evenpsychological terms this refusal is both dogmatic and as will be argued below unaccept able on analytical grounds this reduction of explanation and thereby causality solely to individuals has a furtherimplication the explanation of social phenomena proceeds even by a circuitous route

competition among non life insurers under solvency constraints a game theoretic approach we formulate a noncooperative game to model competition for policyholders among non life insurance companies taking into account market premium solvency level market share and underwriting results we study nash equilibria and stackelberg equilibria for the premium levels and give numerical illustrations

dynamic kidney exchange we study how barter exchanges should be conducted through a centralized mechanism in a dynamically evolving agent pool with time and compatibility based preferences we derive the dynamically efficient two way and multi way exchange mechanisms that maximize total discounted exchange surplus recently several live donor kidney exchange programs were established to swap incompatible donors of end stage kidney disease patients since kidney exchange can be modeled as a special instance of our more general model dynamically efficient kidney exchange mechanisms are derived as corollaries we make policy recommendations using simulations

domestic currency appreciation and foreign capital inflows what comes first chile 1977 1982 abstract the purpose of this paper is to find granger causality relations between the real exchange rate the inflow of foreign capital interest rate arbitrage and the terms of trade in a representative indebted developing country chile this is done for a time period in which chile went from an unprecedented expansion 1977 1981 to a severe recession 1982 the paper confronts two competing hypotheses that purport to explain such behavior hypothesis one claims that causality went from the real exchange rate affected by nominal exchange rate policy to capital inflows in what could be termed a current account deficit induced demand for foreign funds hypothesis two posits a causality that ran the other way from capital inflows to the real exchange rate in which case the exogenous inflows of foreign money implied a current account deficit special attention is paid to the role played by two other related factors interest rate arbitrage and terms of trade variations by applying innovation accounting techniques based on estimated vector autoregressions support is found for the second of these hypotheses thus the real issue in chile and in many other currently indebted latin american countries should be the timing and extent of the capital account liberalization process carried out during the period

the microfoundations project in general equilibrium theory the author 1 argues that the long lived microfoundations project based on general equilibrium models has come to an end and 2 shows that non walrasian models intended to provide microfoundations for macroeconomics are inadequate the arguments are derived from the sonnenschein mantel debreu smd demonstration of the arbitrariness of aggregate excess demands in general equilibrium models of the walrasian arrow debreu mckenzie type the issues raised have significance for the proper method of modeling macroeconomic phenomena for instance the smd results have led a growing number of general equilibrium theorists to make assumptions concerning macroeconomic structure in order to analyze other regularities at the macro level these points validate the position that systematic macroeconomic phenomena are intrinsically macroeconomic copyright 1994 by oxford university press

the pricing of manufactured goods during trade liberalization evidence from chile israel and korea this paper is an investigation of price setting behavior in chile israel and korea when each of these countries moved from a fairly closed to a more open international trade regime in some cases the intensification of the opening resulted from real appreciation rather than from a formal adjustment in tariff rates as in chile 1980 82 and israel 1983 84 the central thesis of this paper is that the structural price equation for import competing manufactured goods changes with the degree of openness to trade when the economy is fairly closed the main weight is commanded by domestic cost variables and excess demand and foreign prices only affect pricing through their effects on imported material prices during trade liberalization the rate of change of prices of an increasing proportion of manufacturing goods begins to be influenced by the landed cost of similar imports but domestic variables still have a role because selected domestic manufactured goods are considered imperfect substitutes for internationally traded products empirical results from time varying parameter estimation show that domestic currency prices of imports become progressively more important during the liberalization processes in the three countries

learning about the future and dynamic efficiency we analyze the conditions under which an efficient allocation of resources is achievable in a dynamic private values setting where the designer gradually learns about the distribution of agents values as an application consider the sequential allocation of scarce spectrum to emerg ing technologies whenever a new technology appears a benevolent designer is faced with a problem should he allocate a valuable chunk of spectrum right now while forfeiting for a long period of time the option of allocating it to a possibly superior future technology it makes sense to assume here that current firms have a better knowledge of their technological prow ess than the designer and that the designer s assessment of future technological possibilities is improved by observing the current technology if technology owners are strategic we show below that the learning process about the future disturbs the ability to extract the information necessary for efficient decision making another good example is hiring by an organization that fills positions at different hierarchy levels over time while all candidates prefer higher level positions some aspect of their ability to perform the needed tasks at each level is privately known to the candidates if contracts with current employees are difficult to adjust the designer must carefully compare the quality of present candidates which can serve as a signal about the market to the expected quality of candidates that may become available in the future finally consider a firm allocating franchises in a country where it did not operate before and where contractual clauses or other impediments prevent reallocation during a significant period of time local potential franchisees may have some superior information regarding future prof itability in the respective market and hence the elicitation of private information is crucial for a franchisor that is supposed to get a share of the future profits

the existence of equilibrium in discontinuous economic games i theory the article presents information about the existence of equilibrium in discontinuous economic games in this paper and its sequel presents study the existence of nash equilibrium in games where agents payoff functions are discontinuous the enquiry is motivated by a number of recent studies that have uncovered serious existence problems in seemingly innocuous economic games in the sequel to this paper authors have explained the utility function in the economic games referred to earlier are neither continuous nor quasi concave however they demonstrate that the payoff functions in mildly modified versions of these constructs exhibit two weaker forms of continuity which together with the requirement of quasi concavity suffice for the existence of an equilibrium from this one may conclude that at least in the modified versions of these models discontinuities in the payoff functions are not the real source of the problem rather it is the failure of the payoff functions to the quasi concave which is responsible for the non existence of equilibrium these observations bear on the existence of nash equilibrium in pure strategies

trade democracy and the gravity equation abstract does democracy affect trade there are several channels by which democracy may affect trade with differing implications first democratization in the exporting country can improve product quality and reduce trade costs increasing bilateral trade second democratization in the importing country may increase trade barriers and thus reduce imports in this paper i analyze the effect of democracy on trade by augmenting the gravity equation with democracy using a rich panel data set and controlling for the endogeneity of democracy i find empirical evidence consistent with the hypothesis that democracy fosters trade this finding is robust to various econometric methods and to the use of disaggregated specifications

consumer heterogeneity and strategic quality decisions though recent studies show that quality differentiation is an equilibrium outcome products of similar qualities frequently are observed in the marketplace this inconsistency may be explained by incorporating consumer heterogeneity along unobservable attributes into a model of competition in this paper consumers not only take into account the quality and price of a product but also their heterogeneous tastes along other attributes which are unobservable to firms we investigate the effect of heterogeneity along the unobservable attributes on both quality and price equilibrium in a two stage game framework we show that when consumers are sufficiently heterogeneous along the unobservable attributes the firms offer products of identical qualities in equilibrium under low levels of heterogeneity along the unobservable attributes however our results are consistent with past research which argues for quality differentiation

coalitional strategy proof house allocation abstract we consider house allocation without endowments we show that there is a unique maximal domain including all strict preferences on which efficiency and coalitional strategy proofness are compatible a preference relation belongs to the unique maximal domain if it is a strict descending ranking of houses to a certain house and indifference holds over it and the remaining houses we also show that on this domain mixed dictator pairwise exchange rules are the only rules satisfying efficiency and coalitional strategy proofness journal of economic literature classification numbers c78 d63 d71

matching with branch of choice contracts at the united states military academy branch selection is a key decision in a cadet s military career cadets at usma can increase their branch priorities at a fraction of slots by extending their service agreement this real life matching problem lls an important gap in market design literature although priorities fail a key substitutes condition the agent optimal stable mechanism is well dened and in contrast to the current usma mechanism it is fair stable and strategy proof adoption of this mechanism benets cadets and the army this new

spatial price competition a semiparametric approach we investigate the nature of price competition among firms that produce differentiated products and compete in markets that are limited in extent we propose an instrumental variables series estimator for the matrix of cross price response coefficients demonstrate that our estimator is consistent and derive its asymptotic distribution our semiparametric approach allows us to discriminate among models of global competition in which all products compete with all others and local competition in which products compete only with their neighbors we apply our semiparametric estimator to data from u s wholesale gasoline markets and find that in this market competition is highly localized

is the firm an individual this paper shows how three new institutionalist theories try but ultimately fail to support the firm as individual thesis first marx hart s idea of property rights and coase williamson s notion of transaction costs are insufficient to substantiate the market firm dichotomy second hayek s constructionist view presents the firm as opposed to the market as a designed order no different from artifacts such as tables and cars third vanberg s constitutionalist theory also fails to support the firm as individual thesis the paper suggests that the consented goal notion is a fruitful ground upon which to build the firm as individual thesis

a model of imperfect competition with keynesian features the recent literature on the reappraisal of keynes has viewed keynesian equilibria as arising when prices are fixed and effective demands and supplies are equilibrated through the adjustment of quantities one problem with this approach is that it lacks a theory of price determination in particular of why prices are fixed in the present paper we show that a number of keynesian features arise in a model in which prices are fully flexible but where agents have some monopoly power one advantage of this approach is that it provides a theory of the determination of both prices and quantities

efficient dynamic barter exchange we study dynamic matching policies in a stochastic marketplace for barter with agents arriving over time each agent is endowed with an item and is interested in an item possessed by another agent homogeneously with probability p independently for all pairs of agents three settings are considered with respect to the types of allowed exchanges a only two way cycles in which two agents swap items b two way or three way cycles c unbounded chains initiated by an agent who provides an item but expects nothing in return we consider the average waiting time as a measure of efficiency and find that the cost outweighs the benefit from waiting to thicken the market in particular in each of the above settings a policy that conducts exchanges in a greedy fashion is near optimal further for small p we find that allowing three way cycles greatly reduces the waiting time over just two way cycles and conducting exchanges through a chain further reduces the waiting time significantly thus a centra

the approach of institutional economics this paper assesses the old institutional economics it emphasizes the importance of key old institutionalist themes concerning the necessity of habits and rules and the role of institutions a problem in the alternative theoretical program of the new institutionalism is the untenability of its assumption of an original institution free market or state of nature even optimizing behavior requires the prior existence of habits and rules although it still lacks a complete and systematic theory the evolutionary approach of the old institutionalists tackles the problem of the interactive relationship of actor to structure without analytical reduction to one or the other

demand for differentiated products discrete choice models and the characteristics approach we propose a specific characteristics framework in order to construct linkages between alternative conceptual approaches to modelling product differentiation first it is shown that a demand system which satisfies the gross substitutes property imposes specific requirements on the locations of products in particular the dimension of the characteristics space must be larger than or equal to the number of products minus one we then identify a method for casting a given demand system subject to certain restrictions into our characteristics framework this is illustrated for the logit probit and linear probability models of discrete choice theory finally we find a characteristics representation of the ces representative consumer

sequentially optimal mechanisms this paper establishes that posting a price in each period is a revenue maximizing allocation mechanism in a finite period model without commitment a risk neutral seller has one object to sell and faces a risk neutral buyer whose valuation is private information and drawn from an arbitrary bounded subset of the real line the seller has all the bargaining power she designs a mechanism to sell the object at t but if trade does not occur at t she can propose another mechanism at t 1 we show that posting a price in each period is an optimal mechanism a methodological contribution of the paper is to develop a procedure to characterize optimal dynamic incentive schemes under non commitment that is valid irrespective of the structure of the agent s type 2006 the review of economic studies limited

multiplicity of equilibria and comparative statics conditions that guarantee the uniqueness of equilibrium in models of economic competition are crucial to applications of these models in exercises of comparative statics until now most of the attention given to the uniqueness question has been focused on pure exchange economies in this paper we use a topological index theorem to derive necessary and sufficient conditions for the uniqueness of equilibrium in economies with production unfortunately conditions that imply uniqueness appear to be too restrictive to have much applicability we argue for example that the only economically interpretable restrictions that imply uniqueness are either that the demand side of an economy behaves like a single consumer or that the supply side is an input output system our results suggest a need for reformulation of the comparative statics method

heterogeneity biases distributional effects and aggregate consumption an empirical analysis using stratified microdata using stratified microdata from the canadian famex 78 86 surveys this paper investigates whether observed heterogeneity in marginal propensities to consume across strata actually hinders the aggregation process despite significant heterogeneity in marginal responses the divergences between aggregate predicted consumption and the predictions from a model that uses average strata responses are found to be small whenever the strata demands are approximatively linear at the mean and the commodity group considered is not a luxury good on the other hand some cross sectional estimates obtained by pooling the strata are shown to be contaminated by unwanted cross moments further the analysis reconciles the fact that while there exists significant heterogeneity in consumer demands the related distributional effects in the aggregate equation have not been found to be important

variety and size regulation in discrete choice oligopoly imperfectly competitive markets for a differentiated product may underprovide brand variety when consumer tastes for brands are highly heterogeneous we show that when the brands in question are indivisible in consumption and each consumer buys a customized quantity or size of the preferred brand only a welfare improvement can be obtained by regulating the size of purchase we study neutral size regulation which requires that the size of purchase be set equal to the size that would prevail in the absence of regulation this improves brand variety and consumer surplus provided consumer tastes are sufficiently heterogeneous

the new keynesian view of aggregate demand some reflections from a classical sraffian standpoint the paper argues that the derivation of the aggregate demand curve in the new keynesian literature is insufficient to provide the theoretical ground for the use to which it is usually put namely as a theoretical basis for the claim that long run wage and price flexibility would push a capitalist economy to the full employment or natural level of output it is argued that the derivation solely on the basis of the propositions about optimising household consumption expenditures is insufficient to guarantee a decreasing aggregate demand function without circular reasoning this point is clarified by use of a very simple two commodity production model of long run steady states due to spaventa and nell to guarantee a decreasing aggregate demand function the new keynesian approach must invoke the kinds of propositions used in more traditional derivations propositions which themselves are in question on capital theoretic grounds

incentive compatibility in a market with indivisible goods abstract in a market in which each trader s initial endowment is one unit of an indivisible good there exists an incentive compatible procedure for reaching a competitive allocation this contrasts with some recent results for similar problems

localized competition multimarket operation and collusive behavior this paper studies collusive behavior in a repeated oligopoly model with localized competition also reinterpreted as a model of multimarket operation private information about the rivals past actions naturally arises from these product market structures the resulting communication problems imply that firms should not adopt strategies with too severe punishments infinite grim punishments may be too severe for large discount factors the standard stick and carrot punishments from the perfect public information model are always too severe for all discount factors modified stick and carrot punishments can still be used though for a smaller range of discount factors than the standard stick and carrot punishments

testing capital account liberalization without forward rates another look at chile 1979 1982 abstract the paper offers a way to test the impact of capital account liberalization on domestic interest rates when proxies for expectations of depreciation are unavailable the model is tested on the well understood japanese experience in 1979 1980 and then applied to the chilean liberalization from 1979 1982 the evidence points to chilean monetary authorities retaining significant control over interest rates across the period and offers support to an evolving interpretation of the period that stresses the excessive optimism about the reforms rather than their lack of credibility as the source of their ultimate collapse

bidding for army career specialties improving the rotc branching mechanism motivated by the low retention rates of us military academy and reserve officer training corps graduates the army recently introduced incentives programs in which cadets could bid 3 years of additional service obligation to obtain higher priority for their desired branches the full potential of this incentives program is not utilized because of the rotc s deficient matching mechanism i propose a design that eliminates these shortcomings and mitigates several policy problems the army has identified in contrast to the rotc mechanism my design utilizes market principles more extensively and it is a hybrid between a market mechanism and a priority based allocation mechanism