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

iterated regret minimization a new solution concept abstract for some well known games such as the traveler s dilemma or the centipede game traditional game theoretic solution concepts most notably nash equilibrium predict outcomes that are not consistent with empirical observations we introduce a new solution concept iterated regret minimization that exhibits the same qualitative behavior as that observed in experiments in many games of interest including traveler s dilemma the centipede game nash bargaining and bertrand competition as the name suggests iterated regret minimization involves the iterated deletion of strategies that do not minimize regret

efficient mechanisms for bilateral trading we consider bargaining problems between one buyer and one seller for a single object the seller s valuation and the buyer s valuation for the object are assumed to be independent random variables and each individual s valuation is unknown to the other we characterize the set of allocation mechanisms that are bayesian incentive compatible and individually rational and show the general impossibility of ex post efficient mechanisms without outside subsidies for a wide class of problems we show how to compute mechanisms that maximize expected total gains from trade and mechanisms that can maximize a broker s expected profit journal of economic literature classification number 026

involuntary unemployment in economies with efficient risk sharing abstract we study economies where employment lotteries determine random layoffs and incomes for employed and unemployed agents allocate risk efficiently we ask for which specifications are unemployed agents worse off a situation we call involuntary unemployment we show unemployed agents are worse off iff an exogenous increase in wealth decreases aggregate unemployment in a monetary economy we show that in equilibrium the unemployed are worse off iff high inflation implies high unemployment our model also generates nominal wage stickiness as an equilibrium phenomenon but neither involuntary unemployment nor nominal stickiness implies these economies are operating inefficiently or are out of equilibrium

the stabilizing role of government size abstract this paper presents an analysis of how alternative models of the business cycle can replicate the stylized fact that large governments are associated with less volatile economies our analysis shows that adding nominal rigidities and costs of capital adjustment to an otherwise standard rbc model can generate a negative correlation between government size and the volatility of output however in the model we find that the stabilizing effect is only due to a composition effect and it is not present when we look at the volatility of private output given that empirically we also observe a negative correlation between government size and the volatility of consumption we modify the model by introducing rule of thumb consumers in this modified version of our initial model we observe that consumption volatility is also reduced when government size increases in similar way to the observed pattern in oecd economies over the last 45 years

anticipating regret why fewer options may be better we study preferences over menus which can be represented as if the agent selects an alternative from a menu and experiences regret if her choice is ex post inferior since regret arises from comparisons between the alternative selected and the other available alternatives our axioms reflect the agent s desire to limit her options we prove that our representation is essentially unique we also introduce two measures of comparative regret attitudes and relate them to our representation finally we explore the formal connection between the present work and the literature on temptation

residential spatial growth with perfect foresight and multiple income groups abstract this paper presents explicit solutions for expanding monocentric cities with two or more income groups housing is durable but deteriorates over time and redevelopment cannot take place landlords have perfect foresight the utility function and housing technology are cobb douglas population per capita income and transportation costs per mile change at constant percentage rates the model is solved analytically using an infinite time horizon as development proceeds outward a constant fraction of land is developed with high income housing and the remaining land is reserved for future low income development at any time housing is constructed at one distance for high income consumers and at a lesser distance for low income consumers high income housing is first occupied by high income consumers then filters to low income consumers and is ultimately abandoned low income housing is first occupied by low income households and ultimately abandoned

optimal simple monetary and fiscal rules under limited asset market participation the combination of limited asset market participation and consumption habits generates indeterminacy for empirically plausible calibrations of a business cycle model characterized by price and nominal wage rigidities equilibrium determinacy is restored by demand management policies based on simple fiscal rules in this regard fiscal control of nominal income growth is particularly effective in addition the complementarity between the taylor rule and the fiscal feedback on nominal income growth produces relatively large welfare gains limiting both aggregate and intragroup volatilities

job destruction and propagation of shocks this paper considers propagation of aggregate shocks in a dynamic general equilibrium model with labor market matching and endogenous job destruction cyclical fluctuations in the job destruction rate magnify the output effects of shocks as well as making them much more persistent interactions between capital adjustment and the job destruction rate play an important role in generating persistence propagation effects are shown to be quantitatively substantial when the model is calibrated using job flow data incorporating costly capital adjustment leads to significantly greater propagation

job search and asset accumulation under borrowing constraints this article examines the relationship between wealth accumulation and job search dynamics it proposes a model in which risk averse individuals search for jobs save and borrow to smooth their consumption one motivation for accumulating wealth is to finance voluntary quits in order to search for better jobs using data on men from the national longitudinal survey 1979 cohort i estimate the individual s dynamic decision problem the results show that borrowing constraints are tight and reinforce the influence of wealth on job acceptance decisions namely that more initial wealth and access to larger amounts of credit increase wages and unemployment duration

household debt and fiscal multipliers we study the size of government spending multipliers in a general equilibrium model with search and matching frictions in which we allow for different levels of household indebtedness the main results are a the presence of impatient households and private debt helps to generate government spending multipliers greater than 1 b as financial conditions worsen the size of the government spending multiplier falls c conversely employment vacancies and unemployment multipliers are larger in a credit crunch d the model explains the observed pattern of responses of labour market variables housing prices and private debt to a fiscal shock reasonably well

evolution of urban housing stocks a model applied to baltimore and houston abstract historical simulations of urban residential growth in baltimore and houston based on a model of the growth process which has two distinct components are presented the vintage component utilizes the growth of income and population and an assumption that housing is putty clay to predict the age distribution of the housing stock in each period the spatial component of the model determines where this housing construction will take place according to 1 housing is built on vacant land and 2 the pattern of construction obeys the rules of the standard monocentric models housing is demolished when economically obsolete the putty clay vintage aspect of the model produces fairly accurate city wide vintage distributions but there is much more mixing of vintages and income in baltimore by location than predicted even under monocentric assumptions most favorable to mixing

utilitarianism egalitarianism and the timing effect in social choice problems two theorems are derived about social choice functions which are defined on comprehensive convex subsets of utility allocation space theorem 1 asserts that a linearity condition together with pareto optimality implies that a social choice function must be utilitarian theorem 2 asserts that a concavity condition together with pareto optimality and independence of irrelevant alternatives implies that a social choice function must be either utilitarian or egalitarian these linearity and concavity conditions have natural interpretations in terms of the timing of social welfare analysis before or after the resolution of uncertainties and its impact on social choices

habit formation in consumption and its implications for monetary policy models this paper explores a monetary policy model with habit formation for consumers in which consumers utility depends in part on current consumption relative to past consumption the empirical tests developed in the paper show that one can reject the hypothesis of no habit formation with tremendous condence largely because the habit formation model captures the gradual hump shaped response of real spending to various shocks the paper then embeds the habit consumption specication in a monetary policy model and nds that the responses of both spending and inflation to monetary policy actions are signicantly improved by this modication jel d12 e52 e43

optimal spatial growth of employment and residences abstract this paper examines the location patterns of employment and residences in an urban area characterized by irreversible land use commitments and smoothly growing population it is assumed that all output is shipped to the center of the urban area and that workers have commuting costs of getting to work the optimal solution which is also the equilibrium solution minimizes the present discounted value of aggregate shipping costs plus commuting costs the residential area expands outward over time but a constant fraction of the land is always reserved for future employment development

the effects of government housing policies in a vintage filtering model abstract long run and short run effects of low income government housing policies are examined in a model that treats housing as a durable good which declines in quality over time short run and long run market equilibria are characterized rent subsidies are analyzed in detail and results for other policies are presented

optimal nonlinear pricing by a monopolist with information ambiguity we consider the optimal nonlinear pricing by an ambiguity averse monopolist the monopolist s subjective belief about the distribution of buyers is described by contamination of an additive probability we find that under a maxmin utility decision rule and with a continuum of buyers ambiguity aversion leads to bunching at the bottom in the optimal contract and the distortion at the bottom is reduced other high valuation buyers are offered the same quantity as in the case without ambiguity but they get a greater discount

price dispersion in the lab and on the internet theory and evidence price dispersion is ubiquitous in settings that closely approximate textbook bertrand competition we show that only a little bounded rationality among sellers is needed to rationalize such dispersion a variety of statistical tests based on datasets from two independent laboratory experiments and structural estimates of the parameters of our models suggest that bounded rationality based theories of price dispersion organize the data remarkably well evidence is also presented to suggest that the models are consistent with data from a leading internet price comparison site

private information wage bargaining and employment fluctuations shimer 2005 pointed out that although we have a satisfactory theory of why some workers are unemployed at any given time we don t know why the number of unemployed workers varies so much over time the basic mortensen pissarides 1994 model does not generate nearly enough volatility in unemployment for plausible parameter values this paper extends the mortensen pissarides model to allow for informational rents productivity is subject to publicly observed aggregate shocks and to idiosyncratic shocks that are seen only by the employer it is shown that there is a unique equilibrium provided that the idiosyncratic shocks are not too large the main result is that small fluctuations in productivity that are privately observed by employers can give rise to a kind of wage stickiness in equilibrium and the informational rents associated with this stickiness are sufficient to generate relatively large unemployment fluctuations

spatial growth and redevelopment with perfect foresight and durable housing abstract in this paper i present a theoretical model of the spatial growth of an urban area with durable housing i combine several assumptions that typically complicate the analysis i housing developers have perfect foresight ii the initial development and many waves of redevelopment are considered in each developer s plan and iii the closed city assumption is made so that the time path of population is exogenous and that of consumer utility is endogenous i still obtain explicit solutions for the spatial pattern of urban growth and for the timing of the initial residential development and each successive redevelopment at each distance from the urban center i compare perfect foresight growth to growth with static expectations and i examine the comparative statics of both

rationalizable strategic behavior the notion of equilibrium proposed by nash 19 has come to play a dominant role in economic applications of noncooperative games while analyses of nash equilibria have unquestionably contributed to our understanding of economic behavior it would be unreasonably optimistic to maintain that nash solved the problem of noncooperative strategic choice there is a small literature beginning with ellsberg 6 and a much larger oral tradition which argues that nash behavior is neither a necessary consequence of rationality nor a reasonable empirical proposition in this paper i take the view that although there may be various reasons why an agent might select a nash strategy the notion of an equilibrium has little intrinsic appeal within a strategic context when an agent reaches a decision in ignorance of the strategies adopted by other players rationality consists of making a choice which is justifiable by an internally consistent system of beliefs rather than one which is optimal post hoc this point of view is not original indeed most serious justifications of the nash hypothesis embrace such an approach arguing that agents will expect the game to yield a nash outcome and consequently will choose their equilibrium strategies nevertheless when we think in terms of maximizing utility subject to expectations rather than realizations it becomes clear that the nash hypothesis far from being a consequence of rationality arises from certain restrictions on agents expectations which may or may not be plausible depending upon the game being played we are then quite naturally led to ask are there any restrictions of individuals expectations and hence choices which are required by rationality alone rather than by subjective plausibility this paper is concerned with defining justifying characterizing and refining a criterion for rational strategic choice which i label rationalizability

the general equilibrium effects of fiscal policy estimates for the euro area abstract this paper describes a dynamic stochastic general equilibrium model featuring a fraction of non ricardian agents in order to estimate the effects of fiscal policy in the euro area the model takes into account distortionary taxation on labor and capital income and on consumption while expenditures are broken down into purchases of goods and services compensation of public employees and transfers to households a newly computed quarterly data set of fiscal variables is used our results point to the prevalence of mild keynesian effects of public expenditures in particular although innovations in fiscal policy variables tend to be rather persistent government purchases of goods and services and compensations for public employees have small and short lived expansionary effects on private consumption while innovations in transfers to households show a slightly more sizeable and lasting effect the effects are more significant on the revenue side decreases in labor income and consumption tax rates have sizeable effects on consumption and output while a reduction in capital income tax favors investment and output in the medium run finally our estimates suggest that fiscal policy variables contribute little to the cyclical variability of the main macro variables

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

minimax regret strategies for bargaining over several variables for the sealed bid mechanism for bilateral bargaining we explore models in which each player bids so as to minimize his maximum regret here regret is defined as the difference between the profit the player could have made with the wisdom of hindsight and the profit he actually made we study bargaining over both price and quantity as well as over more general sets of bargaining alternatives with complete and incomplete information in each case there is a minimax regret strategy that is linear in the true value or cost and the minimax regret is not unacceptably large journal qf economic literature classification numbers 022 026

evaluating the performance of the search and matching model abstract does the search and matching model fit aggregate u s labor market data while the model has become an important tool of macroeconomic analysis recent literature pointed to some significant failures in accounting for the data this paper aims to answer two questions i does the model fit the data and if so on what dimensions ii does the data fit the model i e what are the data which are relevant to be explained by the model the analysis shows that the model fits certain specifications of the data on many dimensions though not on all this includes capturing the high persistence and high volatility of most of the key variables the negative co variation of unemployment and vacancies and the behavior of the worker job finding rate a key role in this fit is played by the convexity of hiring costs and the stochastic properties of the separation rate the latter is a major component of the rate discounting the future value of the job worker match the paper offers a workable empirically grounded version of the model for the analysis of aggregate u s labor market dynamics

house prices borrowing constraints and monetary policy in the business cycle i develop a general equilibrium model with sticky prices credit constraints nominal loans and asset prices changes in asset prices modify agents borrowing capacity through collateral value changes in nominal prices affect real repayments through debt deflation monetary policy shocks move asset and nominal prices in the same direction and are amplified and propagated over time the financial accelerator is not constant across shocks nominal debt stabilises supply shocks making the economy less volatile when the central bank controls the interest rate i discuss the role of equity debt indexation and household and firm leverage in the propagation mechanism finally i find that monetary policy should not target asset prices as a means of reducing output and inflation volatility

search nash bargaining and rule of thumb consumers abstract this paper analyses the effects of introducing two typical keynesian features namely rule of thumb rot consumers and consumption habits into a standard labour market search model rot consumers use the margin that hours and wage negotiation provides them to improve their lifetime utility by narrowing the gap in utility with respect to ricardian consumers this margin for intertemporal optimisation has not been studied yet because this class of restricted agents has been mainly used in models with no equilibrium unemployment our approach allows for a deeper study of the effects of shocks on vacancies unemployment hours wages and how they interact as habits increase rot consumers find it optimal after a positive technology shock to negotiate lower hours and higher wages and this mechanism reduces the simulated correlation between the real wage or productivity and total hours to values closer to those obtained empirically thus with the interaction of rot consumers and consumption habits the labour market search model improves significantly in reproducing some of the stylised facts characterising the us labour market

stochastic technical progress smooth trends and nearly distinct business cycles this paper studies a model of random technical progress where technology diffuses at realistically slow rates it fits smooth trends to the sum of gdp series generated by this model and series representing transitory or cyclical fluctuations detrended gdp is then largely unrelated to technical progress the detrending method proposed by rotemberg 1999 reconstructs cyclical variations somewhat more accurately than the hp filter with sufficiently slow diffusion it is also more accurate than a method based on vars fitted to hours and gdp growth consistent with the model s predictions permanent shocks initially depress both hours and output in these vars

rationalizable strategic behavior and the problem of perfection this paper explores the fundamental problem of what can be inferred about the outcome of a noncooperative game from the rationality of the players and from the information they possess the answer is summarized in a solution concept called rationalizability strategy profiles that are rationalizable are not always nash equilibria conversely the information in an extensive form game often allows certain unreasonable nash equilibria to be excluded from the set of rationalizable profiles a stronger form of rationalizability is appropriate if players are known to be not merely rational but also cautious what constitutes rational behavior in a noncooperative strategic situation this paper explores the issue in the context of a wide class of finite noncooperative games in extensive form the traditional answer relies heavily upon the idea of nash equilibrium nash 17 the position developed here however is that as a criterion for judging a profile of strategies to be reasonable choices for players in a game the nash equilibrium property is neither necessary nor sufficient some nash equilibria are intuitively unreasonable and not all reasonable strategy profiles are nash equilibria the fact that a nash equilibrium can be intuitively unattractive is well known the equilibrium may be imperfect introduced into the literature by selten 20 the idea of imperfect equilibria has prompted game theorists to search for a narrower definition of equilibrium while this research some of which will be discussed here has been extremely instructive it remains inconclusive theorists often agree about what should happen in particular games but to capture this intuition in a general solution concept has proved to be very difficult if this paper is successful it should make some progress in that direction the other side of the coin has received less scrutiny can all non nash profiles really be excluded on logical grounds i believe not the standard justifications for considering only nash profiles are circular in nature or make gratuitous assumptions about players decision criteria or beliefs the following discussion of these points is extremely brief due to space constraints more detailed arguments may be found in pearce 18

non cooperative bargaining theory an introduction the paper provides an informal introduction to some of the main themes of the recent literature on non cooperative or sequential bargaining models it focuses in particular on the relationship between the new approach and the traditional axiomatic approach exemplified by nash bargaining theory it illustrates the new insights offered by the non cooperative approach by reference to a detailed analysis of the manner in which the presence of an outside option available to one of the parties will affect the negotiated outcome finally the difficulties which arise in extending this analysis to two person bargaining with incomplete information and to n person bargaining are discussed this is a revised version of the fourth review of economic studies lecture presented in april 1985 at the joint meeting of the association of university teachers of economics and the royal economic society held in oxford the choice of lecturer is made by a panel whose members are currently professors hahn mirrlees and nobay and the paper is refereed in the usual way this paper aims to provide an informal and elementary introduction to an approach to bargaining which has received a great deal of attention over the past few years the approach involves writing down some particular sequence of moves offers and replies to be made over time in the course of negotiations and then looking for a non cooperative equilibrium in the game thus specified in practice a perfect equilibrium or in games of incomplete information a sequential equilibrium while the approach appears at first sight to be very different in spirit from the traditional axiomatic approach in which a bargaining solution is specified by appealing to a number of general requirements which are deemed appropriate on the basis of some a priori considerations the two approaches are in fact complementary while the

uniform spatial growth with perfect foresight and durable housing abstract this paper presents explicit solutions for expanding monocentric cities housing is durable and redevelopment cannot take place landlords have perfect foresight the utility function and housing technology are cobb douglas the population of the city per capita income construction costs and transportation costs per mile change at constant percentage rates the model is solved analytically using an infinite time horizon if the population growth rate is greater less than twice the difference between the growth rates of income and transportation costs development density increases decreases with distance from the city center detailed comparative statics are presented for both open city and closed city growth

robust monopoly pricing we consider a robust version of the classic problem of optimal monopoly pricing with incomplete information in the robust version the seller faces model uncertainty and only knows that the true demand distribution is in the neighborhood of a given model distribution we characterize the pricing policies under two distinct decision criteria with multiple priors i maximin utility and ii minimax regret the equilibrium price under either criterion is lower then in the absence of uncertainty the concern for robustness leads the seller to concede a larger information rent to all buyers with values below the optimal price without uncertainty

urban spatial development with durable but replaceable capital the theory of urban spatial development until recently has been primarily a static theory of economic equilibrium the models of alonso l mills 6 and muth 7 determine a complete spatial equilibrium between the supply and demand for urban land the study of growth or change in such models therefore has been limited exclusively to comparative statics wheaton 8 it should be clear that the central and in many respects unrealistic assumption of such models is that housing capital is neither physically nor economically durable without durability there is no opportunity cost to old capital no barrier to change and no history to an urban area within such a framework a common set of conclusions emerges regarding urban spatial structure residential density and the price per unit of land decline monotonically from the location of employment a greater population results in higher density at all locations while increases in income or decreases in the cost of travel create a more steeply sloped density and price gradient in the last few years there has been a growing awareness that the equilibrium portrayed by such models does not correctly reflect the process of urban development theoretical papers by anas 2 31 and brueckner 4 and an empirical model by harrison and kain 5 develop an alternative theory of urban spatial development in which the process of growth is explicitly modeled and in which capital is completely durable in their models the spatial development of cities occurs incrementally over time in successive rings from the center of employment outwards the development of each ring is done with myopic foresight and is therefore determined exclusively by market conditions at the time of development once built

health insurance choice and risk preferences under cumulative prospect theory an experiment we investigate how consumers choose insurance contracts when using a measure of decision quality based on individual risk preferences for this we use a laboratory experiment with a sequential design first subjects face insurance choices then we elicit risk preferences allowing for different latent decision making theories i e cumulative prospect theory and expected utility theory we find that the vast majority are cumulative prospect theory types analyzing whether subjects choose contracts consistent with their risk preferences we find that about 14 of all participants show inconsistent behavior and low decision quality yet the majority shows consistent behavior and good decision quality our results suggest that one explanation for inconsistent choices is the application of heuristics

regret theory a bold alternative to the alternatives in their famous 1982 paper in this journal loomes and sugden introduced regret theory now more than 30 years later the case for the historical importance of this contribution can be made

labor market dynamics under long term wage contracting abstract recent research seeking to explain the strong cyclicality of us unemployment emphasizes the role of wage rigidity this paper proposes a micro founded model of wage rigidity an equilibrium business cycle model of job search where risk neutral firms post optimal long term contracts to attract risk averse workers equilibrium contracts feature wage smoothing limited by the inability of parties to commit to contracts the model is consistent with aggregate wage data if neither worker nor firm can commit producing too rigid wages otherwise wage rigidity does not lead to a substantial increase in the cyclical volatility of unemployment

landscape preferences and patterns of residential development abstract i analyze a model of residential location choice where people derive utility from their proximity to open space when people have such landscape preferences then 1 equilibrium residential development is mixed with undeveloped land 2 equilibrium land price gradients depend sensitively on how land markets are organized are not generally monotonic and may or may not reflect the value of open space and 3 dynamic equilibria generally have the property that more remote areas are developed before more central areas finally when compared to optimal development equilibrium development houses too many residents too close together and remote areas are developed too soon these results imply that equilibrium development may not be sprawling enough and that policies to encourage infill development are not welfare improving

self confirming equilibrium rium path of play thus if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs even though beliefs about play at off path information sets need not be correct we characterize the ways in which self confirming equilibria and nash equilibria can differ and provide conditions under which self con firming equilibria correspond to standard solution concepts nash equilibrium and its refinements describe a situation in which i each player s strategy is a best response to his beliefs about the play of his opponents and ii each player s beliefs about the opponents play are exactly correct we propose a new equilibrium concept self confirming equilibrium that weakens condition ii by requiring only that players beliefs are correct along the equilibrium path of play thus each player may have incorrect beliefs about how his opponents would play in contingencies that do not arise when play follows the equilibrium and moreover the beliefs of different players may be wrong in different ways the concept of self confirming equilibrium is motivated by the idea that noncooperative equilibria should be interpreted as the outcome of a learning process in which players revise their beliefs using their observations of previous play suppose that each time the game is played the players observe the actions chosen by their opponents but that players do not observe the actions their opponents would have played at the information sets that were not reached along the path of play then if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs so the equilibrium is self confirming in the weak sense of not being inconsistent with the evidence by analogy with the literature on the bandit problem e g rothschild 1974 one might expect that a non nash self confirming equilibrium can be the outcome of plausible learning processes this point was made by fudenberg and

spatial aspects of housing quality density and maintenance this paper is concerned with how housing quality maintenance and structural density and household income vary over location when the housing stock is durable these issues have been investigated before but the models employed have been restrictive for example in brueckner 1981 maintenance expenditures are constrained not to vary through time in sweeney 1974a 1974c the maintenance technology is defined in a way which does not allow upgrading or even holding housing at constant quality and in ho man and pines 1982 there is no clear distinction between construction and maintenance and their model describes a long run accumulation of housing capital as a process of gradual upgrading a similar approach can be found in the nonspatial model of von rabenau 1976 in an earlier paper amott et al 1983 adp hereafter we extended the analysis of landlord builder behavior by allowing the unrestricted construction maintenance policy in this paper we use the model of adp to investigate some spatial aspects of the filtering process in a stationary state housing market in the process we examine the robustness of some results in the literature

urban economic theory land use and city size this book examines the economic reasons why people choose to live where they live and develops through analysis of the bid rent function a unified theory of urban land use and city size the first part of the book explicates the basic theory of urban land use and optimal city size residential location behavior of households is examined in a microeconomic framework and equilibrium and optimal patterns of residential land use are discussed the corresponding equilibrium and optimal city sizes are studied in a variety of contexts part two extends the classical theories of von thunen and alonso with the addition of externality factors such as local public goods crowding and congestion and racial prejudice the rigorous mathematical approach and theoretical treatment of the material make urban economic theory of interest to researchers in urban economics location theory urban geography and urban planning

business cycles unemployment insurance and the calibration of matching models this paper theoretically and empirically documents a puzzle that arises when an rbc economy with a job matching function is used to model unemployment the standard model can generate sufficiently large cyclical fluctuations in unemployment or a sufficiently small response of unemployment to labor market policies but it cannot do both variable search and separation finite ui benefit duration efficiency wages and capital all fail to resolve this puzzle however either sticky wages or match specific productivity shocks can improve the model s performance by making the firm s flow of surplus more procyclical which makes hiring more procyclical too

habit formation and intertemporal substitution in individual food consumption individual food consumption data are used to examine three issues first is food consumption linked intertemporally at the individual level second does the association between current and past consumption reflect habit or heterogeneity third what do the estimates imply about the intertemporal elasticity of substitution the authors find that habit matters that controlling for heterogeneity reduces estimated habit effects and that the product of the estimated intertemporal elasticity of substitution and the risk aversion parameter is less than one these results all lead to rejection of time separable specifications of intertemporal consumption behavior copyright 1996 by mit press

equilibria of the sealed bid mechanism for bargaining with incomplete information we study the nash equilibria of the sealed bid bargaining mechanism with incomplete information a nonzero sum game for the case of uniform priors we describe two uncountably numerous families of equilibria the first has differentiable strategies in the second the strategies are step functions the efficiencies of these equilibria range from second best to zero for independent nonuniform priors we show that a similar situation obtains these results seem discouraging with regard to using the sealed bid mechanism in practice the mechanism might be salvaged however if bargainers turn out to confine themselves to linear strategy equilibria

spatial patterns of residential development abstract a simple dynamic model of residential development with durable housing where all households are identical and all developers have perfect foresight is studied it is shown that unlike the case of static models it is quite possible that house size decreases and thus population density increases with distance from the city center and that the house rent curve has positive gradient in certain area

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

regret aversion and opportunity dependence this paper provides an axiomatic model of decision making under uncertainty in which the decision maker is driven by anticipated ex post regrets our model allows both regret aversion and likelihood judgement over states to coexist also we characterize two special cases minimax regret with multiple priors that generalizes savage s minimax regret and a smooth model of regret aversion

strategic uncertainty and equilibrium selection in discontinuous games abstract we introduce the new concept of prudent equilibrium to model strategic uncertainty and prove it exists in large classes of discontinuous games when the game is better reply secure we show that prudent equilibrium refines nash equilibrium in contrast with the current literature we don t use probabilities to model players strategies and beliefs about other players strategies we provide examples first price auctions location game nash demand game etc where prudent equilibrium concept removes most non intuitive solutions of the game

the equal loss principle for bargaining problems abstract we introduce a new bargaining solution which we call the equal loss solution this solution equalizes across agents the losses from the ideal point two characterizations of the solution are presented by formulating axioms specifying how bargaining solutions should respond to changes in the feasible set and the ideal point

business cycles and labor market search the quantitative implications of labor market search for economic fluctuations are evaluated in the context of a real business cycle model incorporating labor market search into the model is found to improve its empirical performance along several dimensions in particular hours now fluctuate substantially more than wages and the contemporaneous correlation between hours and productivity falls in addition the model replicates the observation that output growth displays positive autocorrelation at short horizons overall the empirical results suggest that the labor market search environment embodies a quantitatively important propagation mechanism copyright 1996 by american economic association

costs of adjustment and the spatial pattern of a growing open city this paper investigates the effect of costs of adjustment on the dynamic characteristics of intra urban resource allocation the analysis is concentrated on the development pattern of an open city within a system of many cities both in steady state and in variable state economies competitive equilibrium of the urban system as a whole is also discussed and compared to pareto optimum allocation some of the results that characterize the resource allocation under static analysis are reestablished for the dynamic case as well but others that follow from comparative statics are shown to be incorrect under the dynamic analysis

the fundamentals of land prices and urban growth abstract in a very simple model in which capital is durable and landowners have perfect foresight the price of urban land has four additive components the value of agricultural land rent the cost of conversion the value of accessibility and the value of expected future rent increases a growth premium in rapidly growing cities the growth premium may easily account for half of the average price of land and may create a large gap between the price of land at the boundary minus conversion cost and the value of agricultural land rent

household debt and labor market fluctuations abstract the co movements of labor productivity with output total hours vacancies and unemployment have changed since the mid 1980s this paper offers an explanation for the sharp break in the fluctuations of labor market variables based on endogenous labor supply decisions following the mortgage market deregulation we set up a search model with efficient bargaining and financial frictions in which impatient borrowers can take an amount of credit that cannot exceed a proportion of the expected value of their real estate holdings when borrowers equity requirements are low the impact of a positive technology shock on the marginal utility of consumption is strengthened which in turn results in lower hours per worker and higher wages in the bargaining process this shift in labor supply discourages firms from opening vacancies reducing the impact of the shock on employment we simulate the effects of an increase in both the loan to value ratio and the share of borrowers in total population our exercise shows that the response of labor market variables might have been substantially affected by the increase in household leverage in the us in the last twenty years

on the existence of pure and mixed strategy nash equilibria in discontinuous games a game is better reply secure if for every nonequilibrium strategy x and every payoff vector limit u resulting from strategies approaching x some player i has a strategy yielding a payoff strictly above u i even if the others deviate slightly from x if strategy spaces are compact and convex payoffs are quasiconcave in the owner s strategy and the game is better reply secure then a pure strategy nash equilibrium exists better reply security holds in many economic games it also permits new results on the existence of symmetric and mixed strategy nash equilibria

common beliefs and the existence of speculative trade abstract this paper shows that if rationality is not common knowledge the no trade theorem of milgrom and stokey fails to hold we adopt monderer and samet s notion of common p belief and show that when traders entertain doubts about the rationality of other traders arbitrarily large volumes of trade as well as rationality may be common p belief for a large p furthermore rationality and trade may simultaneously be known to arbitrary large but finite degree journal of economic theory classification numbers c70 d82 d84

a definition of uncertainty aversion a definition of uncertainty or ambiguity aversion is proposed it is argued that the definition is well suited to modelling within the savage as opposed to anscombe and aumann domain of acts the defined property of uncertainty aversion has intuitive empirical content behaves well in specific models of preference multiple priors and choquet expected utility and is tractable tractability is established through use of a novel notion of differentiability for utility functions called eventwise differentiability

bilateral trade with the sealed bid k double auction existence and efficiency for k in the unit interval the k double auction determines the terms of trade when a buyer and a seller negotiate transfer of an item the buyer submits a bid b and the seller submits an offer s trade occurs if b exceeds s at price kb 1 k s we model trade as a bayesian game in which each trader privately knows his reservation value but only has beliefs about the other trader s value existence of a multiplicity of equilibria is proven for a class of trader s beliefs for generic beliefs however these equilibria are shown to be ex ante inefficient

ambiguity made precise a comparative foundation the theory of subjective expected utility has been recently extended to allow ambiguity to matter for choice we propose a notion of absolute ambiguity aversion by building on a notion of comparative ambiguity aversion we characterize it for a preference model which encompasses some of the most popular models in the literature we next build on these ideas to provide a definition of unambiguous act and event and show the characterization of the latter as an illustration we consider the classical ellsberg 3 color urn problem and find that the notions developed in the paper provide intuitive answers journal of economic literature classification number d81

growth speculation and sprawl in a monocentric city abstract an economic theory of sprawl in a growing monocentric city is presented where decision makers have perfect foresight leapfrog development and discontinuous land rent functions may occur and be efficient in both an ex post and ex ante sense where the extent of future growth is uncertain decision makers become speculators and the spatial pattern of development is more complicated ex post inefficiency generally occurs

irrationality and ambiguity in extensive games abstract based on a model where deviations from equilibrium play are assumed to identify irrational players who are characterized by ambiguous set valued strategies this paper introduces an equilibrium notion for extensive games with ambiguity averse players that yields a precise interpretation for the counterfactual reasoning usually associated with backward induction the resulting equilibria are always nash equilibria but may not satisfy the conditions required for various refinements of nash equilibrium including those for subgame perfection existence of such equilibria is proved for all two player games and for n player games with perfect information

implementation in minimax regret equilibrium this note studies the problem of implementing social choice correspondences in environments where individuals have doubts about the rationality of their opponents we postulate the concept of minimax regret as our solution concept and show that social choice correspondences that are maskin monotonic and satisfy the no veto power condition are implementable in minimax regret equilibrium for all 0 1