social security liquidity constraints and pre retirement consumption one of the primary goals of the social security retirement program is the maintenance of consumption in old age in the past decade since the pioneering paper by feldstein 13 studies have examined the impact of the system on consumption over the entire life cycle and not just in old age empirical work has tested the impact on consumption of the individual wealth transfers accompanying the introduction of a pay as you go social security system extending this discussion of the impact of social security on pre retirement consumption hubbard 21 has shown in the context of lifetime uncertainty that even an actuarially fair fully funded social security system can raise lifetime consumption hence previous partial equilibrium estimates of the impact of social security on consumption drawn solely from consideration of the intergenerational wealth transfer at the introduction of the system are underestimates of the potential effect 2 an important assumption in the approaches cited above is that of perfect capital markets i e that individuals can borrow against prospective gains from participating in the social security system such an assumption is at variance with actual limitations on borrowing e g upward sloping interest rate schedules collateral requirements and quantity restrictions hayashi 18 found that approximately twenty percent of all consumption in the u s is accounted for by liquidity constrained consumers 3 flavin 16 found that the estimate of the marginal propensity to consume is affected dramatically by the inclusion of proxies for liquidity constraints suggesting that liquidity constraints are an important part of the observed excess sensitivity of consumption to current income since its inception in 1935 old age and survivors insurance oasi provided

on the existence of a strictly strong nash equilibrium under the student optimal deferred acceptance algorithm abstract this study analyzes a preference revelation game in the student optimal deferred acceptance algorithm in a college admission problem we assume that each college s true preferences are known publicly and analyze the strategic behavior of students we demonstrate the existence of a strictly strong nash equilibrium in the preference revelation game through a simple algorithm that finds it specifically i the equilibrium outcome from our algorithm is the same matching as in the efficiency adjusted deferred acceptance algorithm and ii in a one to one matching market it coincides with the student optimal von neumann morgenstern vnm stable matching we also show that i when a strict core allocation in a housing market derived from a college admission market exists it can be supported by a strictly strong nash equilibrium and ii there exists a strictly strong nash equilibrium under the college optimal deferred acceptance algorithm if and only if the student optimal stable matching is pareto efficient for students

walrasian equilibrium with gross substitutes in this paper we study the problem of efficient production and allocation of indivisible objects among a set of consumers we assume that the agents preferences depend on the bundle of objects and the quantity of money they consume furthermore we assume that preferences are quasilinear in money and that agents have a large endowment of money with indivisibilities it is well known that many familiar properties of the utility functions fail to ensure existence in their striking analysis of the matching problem kelso and crawford 5 introduce the gross substitutes gs condition which ensures the non emptiness of the core we propose two new conditions and show that with quasilinearity they are equivalent article id jeth 1999 2531 available online at http www idealibrary com on

capital taxation and accumulation in a life cycle growth model almost all of the serious economic work on savings decisions within the past decade has relied on some variant of the life cycle hypothesis in which savings arise out of individual choices of an optimum lifetime consumption path this paper reexamines the incidence and welfare consequences of capital income taxes within a realistic life cycle model the results suggest that the elimination of capital income taxation would have very substantial economic effects for example a complete shift to consumption taxation might raise steady state output by as much as 18 percent and consumption by 16 percent the long run welfare gain from such a shift would for plausible parameter values exceed 150 billion annually stated somewhat differently shifting to consumption taxation would raise the lifetime utility of the representative consumer by the equivalent of about six years income in the new steady state these estimates dwarf estimates of the static welfare cost of taxation and significantly exceed even extreme previous estimates of the dynamic loss this study departs from earlier analyses of the effects of taxes on capital income in several respects probably the most important difference between this treatment and most preceding ones lies in the assumptions about the interest elasticity of saving it is shown below that the common two period formulation of saving decisions yields quite misleading results a more realistic model of life cycle savings demonstrates that for a wide variety of plausible parameter values savings are very interest elastic this implies that shifting away from capital income taxation would significantly increase capital formation making possible long run increases in consumption many studies of the welfare effects of capital income taxation have ignored the general equilibrium effects of increased capital formation in an economy with life cycle savings there is no presumption that the undistorted growth path corresponds to any sort of social optimum as peter diamond has shown life cycle savings can lead to a steady state capital intensity either greater or less than the golden rule level more generally it is clear that there is no reason to believe that a life cycle economy will maximize any particular intertemporal social welfare function a fundamental tenet of welfare evaluation is that preexisting distortions must be considered in evaluating the consequences of tax changes the results presented in this paper take explicit account of the nonoptimal character of the no tax steady state this explains in large part why such a sizeable welfare effect of capital taxes is found in an economy far from the golden rule level of capital intensity there are substantial gains in steady state consumption achievable through increased capital formation section i of the paper examines the aggregate savings function in a continuous time life cycle framework the second section clarifies the differences between wage and consumption taxes an aggregate production function is added to complete the model in the third section the effects of changes in capital taxes on both steady state incidence and welfare are considered within a general equilibrium framework the final section of the paper discusses some implications of the results and suggests areas which appear to warrant further study assistant professor of economics massachusetts institute of technology and research analyst national bureau of economic research i am grateful to alan auerbach martin feldstein laurence kotlikoff to the participants in the nber workshop on business taxation and to the harvard public finance seminar for useful discussions james poterba and james buchal performed the numerical calculations

near feasible stable matchings with couples the national resident matching program seeks a stable matching of medical students to teaching hospitals with couples stable matchings need not exist nevertheless for any student preferences we show that each instance of a matching problem has a nearby instance with a stable matching the nearby instance is obtained by perturbing the capacities of the hospitals in this perturbation aggregate capacity is never reduced and can increase by at most four the capacity of each hospital never changes by more than two

on stable and strategy proof rules in matching markets with contracts abstract this paper studies stable and one sided strategy proof rules in many to one matching markets with contracts not assuming any kind of substitutes condition or the law of aggregate demand we obtain the following results first the number of stable and strategy proof rules is at most one second the doctor optimal stable rule whenever it exists is the unique candidate for a stable and strategy proof rule third a stable and strategy proof rule whenever it exists is second best optimal for doctor welfare in that no individually rational and strategy proof rule can dominate it this last result is further generalized to non wasteful and strategy proof rules due to the weak assumptions our analysis covers a broad range of markets including cases where a unique stable and strategy proof rule is not equal to the one induced by the cumulative offer process or the deferred acceptance algorithm

internet advertising and the generalized second price auction selling billions of dollars worth of keywords we investigate the generalized second price gsp auction a new mechanism used by search engines to sell online advertising although gsp looks similar to the vickrey clarke groves vcg mechanism its properties are very different unlike the vcg mechanism gsp generally does not have an equilibrium in dominant strategies and truth telling is not an equilibrium of gsp to analyze the properties of gsp we describe the generalized english auction that corresponds to gsp and show that it has a unique equilibrium this is an ex post equilibrium with the same payoffs to all players as the dominant strategy equilibrium of vcg

tax policy the interest elasticity of saving and capital accumulation numerical analysis of theoretical models increasing disillusionment with traditional empirical methods is having a major impact on research methodology which is increasingly turning to simulation analysis based on theoretical models and assumed parameter values in research on saving and wealth accumulation there have been several recent studies consisting of simulation of theoretical models based on the life cycle model a particular focus has been tax policy and capital formation which is the area of concentration of this paper the aim is to analyze in a theoretical simulation context the impact on saving and wealth of an increase in the after tax rate of return to saving generated by a cut in the tax rate on income from capital this paper suggests that such simulation analysis while instructive as to the behavior of the class of models examined and as to the critical channels of influence does not yield a theoretical presumption in favor of cutting taxes on income from capital as a means of stimulating capital formation the development of this literature derives in part from disillusionment with traditional empirical methods many such papers begin by listing a litany of the problems involved in the usual type of empirical analysis before proceeding to simulation of theoretical structures the implicit conclusion at times appears to be that because of the daunting problems of standard empirical methodology the results derived from it can be ignored and that empirical magnitudes can perhaps be discovered by deductive means the temptation to think of the precise numerical results derived from theoretical simulation as empirical can be rather strong it needs to be reemphasized that empirical magnitudes can only be determined by empirical studies in section i the theoretical structure of a zero bequest life cycle model2 is outlined and several numerical simulations of this model are presented these simulations highlight interesting and nontrivial interactions of theoretical parameters and also demonstrate the difficulty involved in attempts to develop robust aggregate implications from such a framework for instance it is argued that summers claim to have developed a prima facie theoretical case for a high interest elasticity of savings 1981a p 537 does not stand up to sensitivity analysis a small change in the assumed rate of pure time preference or in other parametric assumptions generate otherwise plausible cases in which the interest elasticity of aggregate saving is low the experiments conducted in section i are partial equilibrium in the sense that the interest rate is changed exogenously which changes savings and hence the capital stock but the feedback effect of the capital international monetary fund this paper derives from chs 2 and 3 of my doctoral dissertation completed during a research fellowship at the brookings institution financial support was received from brookings and the social science research council i am grateful to henry aaron barry bosworth maxim engers irwin friend laurence kotlikoff franco modigliani joseph pechman duncan ripley robert shiller patricia stack and my supervisor albert ando for comments and guidance on earlier drafts none of the above institutions or individuals is responsible for the views expressed or any remaining errors for example see james tobin and walter dolde betsy white lawrence summers 1978 1981a b g moore alan auerbach and laurence kotlikoff and auerbach kotlikoff and j skinner 2it is popular to establish a sharp dichotomy between life cycle models and bequest models this taxonomy ignores the frequent references to the potential significance of bequests in the writings of the originators of the life cycle hypothesis a distinction between zero bequest life cycle models and life cycle models incorporating bequests is more accurate in terms of doctrinal history see for example albert ando and franco modigliani and modigliani and richard brumberg

the contribution of environmental amenities to low income housing a comparative study of bangkok and jakarta central and local governments and their creditors are increasingly interested in cost recovery for public services these strategies have two aims increasing revenues and making a better connection between benefits received and consumer bills this paper estimates a hedonic model for household level data in a rare contrast of slums in two asian mega cities to provide comparative information about how the poor value environmental amenities and basic infrastructure access the results suggest that slum housing prices do reflect differentials in public service access and that rough estimates of the value of access can be cheaply and usefully obtained for planning purposes

compact bid languages and core pricing in large multi item auctions we introduce an auction design framework for large markets with hundreds of items and complex bidder preferences such markets typically lead to computationally hard allocation problems our new framework consists of compact bid languages for sealed bid auctions and methods to compute second price rules such as the vickrey clarke groves or bidder optimal core selecting payment rules when the optimality of the allocation problem cannot be guaranteed to demonstrate the efficacy of the approach for a specific complex market we introduce a compact bidding language for tv advertising markets and investigate the resulting winner determination problem and the computation of core payments for realistic instances of the respective winner determination problems very good solutions with a small integrality gap can be found quickly although closing the integrality gap to find marginally better solutions or prove optimality can take a prohibitively large amount of time our subsequent adaptation of a constraint

a binary conflict ascending price bicap mechanism for the decentralized allocation of the right to use railroad tracks the questions posed for study are motivated by controversies over how sweden might change from a centralized system of railroad management to a decentralized system the central rail administration banverket will retain ownership and maintenance responsibility of the tracks but will sell access to the tracks to private firms the questions are about the mechanism that might accomplish this task parties to the controversy have claimed that the technical aspects of networks will as a matter of principle preclude the operation of any decentralized method this paper explores the properties of a mechanism developed as a challenge to that claim the mechanism is examined in the context of a testbed experimental environment that contains many potential problem causing elements in the tests performed the mechanism operated to efficiently allocate access to the network and it did so for behavioral reasons that are understandable in terms of theory the paper closes with suggestions for further study of environments that might present additional challenges to a mechanism

conversion to a consumption tax the transition in a life cycle growth model this paper examines the transitional losses that may follow conversion from an income tax to a consumption tax even when conversion eventually raises steady state lifetime welfare two recent studies have left the impression that the transitional losses would be large using a life cycle growth model this paper examines two reasons why these studies have probably overestimated the transitional losses the model computes the welfare gains and losses of each age cohort along the transition path it is shown that the greater the bequest motive and subjective discount rate generating the particular initial income tax steady state the smaller would be the transitional losses similarly a policy of age phasing would reduce the losses the results demonstrate the importance of examining the transition path whenever a policy change alters capital accumulation

the permanent income hypothesis estimation and testing by instrumental variables the permanent income hypothesis with rational expectation is restated estimated and tested by an instrumental variables technique on the postwar u s aggregate time series data the hypothesis is accepted on a consumption series which includes service flows from consumer durables if the consumption series is the one in the national income and product accounts the hypothesis is decisively rejected an explanation is suggested to reconcile the conflicting test results

the price of land for housing in trinidad the role of regulatory constraints and implications for affordability institutional and regulatory environments have a profound impact on land markets and prices this paper argues that affordability of land and housing ownership in less developed countries is largely affected by cumbersome land transfer processes and an uncertain building permit approval process it examines the impact of these constraints on land markets and affordability in trinidad by using dowall s land market assessment methodology the paper examines land price changes and land conversion patterns in the east west corridor region of trinidad between 1989 and 1993 while prices of fully registered and serviced land have remained stable during this period unlike many cases of skyrocketing land prices reported in the literature an examination of institutional and regulatory constraints suggests that land prices are likely to increase in the future when demand conditions become more favourable these constraints have certainly played a significant role in the expansion of unauthorised housing settl

efficient advert assignment we develop a framework for the analysis of large scale ad auctions where adverts are assigned over a continuum of search types for this pay per click market we provide an efficient mechanism that maximizes social welfare in particular we show that the social welfare optimization can be solved in separate optimizations conducted on the time scales relevant to the search platform and advertisers here on each search occurrence the platform solves an assignment problem and on a slower time scale each advertiser submits a bid that matches its demand for click throughs with supply importantly knowledge of global parameters such as the distribution of search terms is not required when separating the problem in this way exploiting the information asymmetry between the platform and advertiser we describe a simple mechanism that incentivizes truthful bidding has a unique nash equilibrium that is socially optimal and thus implements our decomposition further we consider models where advertisers ad

stable and strategy proof matching with flexible allotments we introduce a framework of matching with flexible allotments that can be used to model firms with cross division hiring restrictions our framework also allows us to nest some prior models of matching with distributional constraints building upon our recent work on observable substitutability we show that multi division choice functions with flexible allotments enable stable and strategy proof matching these results illustrate the value of clearly mapping when stable and strategy proof matching is possible

untruthful dominant strategies for the deferred acceptance algorithm abstract we examine all dominant strategies for the deferred acceptance algorithm under substitutable and quota filling choice functions we show how untruthful dominant strategies look like our finding leads to the uniqueness of equilibrium outcome despite the possibility of multiple equilibria

social security and private saving new time series evidence in an important article in the journal of political economy martin feldstein 1974 estimated that the introduction of the social security system had reduced personal saving by 50 percent with serious consequences for capital formation and output his conclusion was based on a consumer expenditure function estimated with u s time series data and incorporating a social security wealth variable of his construction this paper presents new evidence that casts considerable doubt on feldstein s conclusion first the social security wealth variable used by feldstein was seriously flawed as a result of a computer programming error simply correcting this error substantially changes the estimated effect of social security on saving second the statistical evidence depends upon assumptions which are embedded in the construction of the social security wealth variable assumptions that are not demonstrably preferable and are in some cases inferior to alternative assumptions these assumptions relate first to how individuals form their expectations about the social security benefits they expect to receive and the social security taxes they expect to pay and second to estimates of the number of workers dependent wives and surviving

uncertainty and optimal social security systems this paper examines the annuity aspect of social security within the framework of an overlapping generations model the duration of life is assumed to be uncertain under a fully funded system demand for social security is determined by each generation so as to maximize expected lifetime utility taking into account the welfare of future generations under a pay as you go system with intergenerational transfers demand for retirement benefits by the working population takes into account taxes paid by descendants it is shown that the two modes of finance are equivalent in terms of all real aggregates effects of changes in expected lifetime and in the birth rate are analyzed starting at the optimal level a compulsory balanced increase in social security taxes and benefits is shown to increase short run savings

urban spatial development in the land policy reform era evidence from beijing this paper examines the characteristics of urban spatial development in beijing and identifies the extent to which these characteristics can be attributed to the emerging land market in beijing as

time horizons lattice structures and welfare in multi period matching markets abstract we analyze a t period two sided one to one matching market without monetary transfers under natural restrictions on agents preferences which accommodate switching costs status quo bias and other forms of inter temporal complementarity dynamically stable matchings exist we propose a new ordering of the stable set ensuring that it forms a lattice we investigate the robustness of dynamically stable matchings with respect to the market s time horizon and frequency of rematching opportunities

the law of aggregate demand and welfare in the two sided matching market abstract in the college admission problem we show that the student optimal stable matching is weakly pareto optimal for students if colleges preferences satisfy substitutability and the law of aggregate demand we also show that both of these properties are important for the result

sorting through search and matching models in economics toward understanding assortative matching this is a self contained introduction to research on search and matching we first explore the nontransferable and perfectly transferable utility matching paradigms and then a unifying imperfectly transferable utility matching model motivated by some unrealistic predictions of frictionless matching we flesh out the foundational economics of search theory we then revisit the original matching paradigms with search frictions we finally allow informational frictions that often arise such as in college student sorting

bayes nash equilibria of the generalized second price auction abstract we develop a bayes nash analysis of the generalized second price gsp auction the multi unit auction used by search engines to sell sponsored advertising positions our main result characterizes the efficient bayes nash equilibrium of the gsp and provides a necessary and sufficient condition that guarantees existence of such an equilibrium with only two positions this condition requires that the click through rate of the second position is sufficiently smaller than that of the first when an efficient equilibrium exists we provide a necessary and sufficient condition for the auction revenue to decrease as click through rates increase interestingly under optimal reserve prices revenue increases with the click through rates of all positions further we prove that no inefficient equilibrium of the gsp can be symmetric our results are in sharp contrast with the previous literature that studied the gsp under complete information

costs of taxation and the size of government existing theory on the form of government suggests that a parliamentary system promotes a larger size of government than does a presidential system this paper extends the existing theory by allowing for distortionary taxation a main result is that if taxation is sufficiently distortionary the parliamentary system may promote a smaller size of government than the presidential system the proposed mechanism appears consistent with several empirical patterns in the data that cannot be explained by other theories

group incentive compatibility for matching with contracts abstract hatfield and milgrom hatfield john william milgrom paul r 2005 matching with contracts amer econ rev 95 913 935 present a unified model of matching with contracts which includes the standard two sided matching and some package auction models as special cases they show that the doctor optimal stable mechanism is strategy proof for doctors if hospitals preferences satisfy substitutes and the law of aggregate demand we show that the doctor optimal stable mechanism is group strategy proof for doctors under these same conditions that is no group of doctors can make each of its members strictly better off by jointly misreporting their preferences we derive as a corollary of this result that no individually rational allocation is preferred by all the doctors to the doctor optimal stable allocation

frontiers in spectrum auction design abstract spectrum auction design has seen number innovations in the recent years regulators have used various types of combinatorial auction formats including simple ascending combinatorial clock auctions and first price sealed bid combinatorial auctions the simultaneous multi round auction smra and the two stage combinatorial clock auction cca are the most wide spread auction formats for spectrum sales to date we provide an accessible overview of strategic problems in these auction formats and summarize research challenges in this field for a broader audience of readers in industrial organization

simplified mechanisms with an application to sponsored search auctions abstract a mechanism can be simplified by restricting its message space if the restricted message spaces satisfy a certain outcome closure property then the simplification is tight for every e 0 any e nash equilibrium of the simplified mechanism is also an e nash equilibrium of the unrestricted mechanism prominent auction and matching mechanisms are tight simplifications of mechanisms studied in economic theory and often incorporate price adjustment features that facilitate simplification the generalized second price auction used for sponsored search advertising is a tight simplification of a series of second price auctions that eliminates the lowest revenue equilibrium outcomes and leaves intact only higher revenue equilibria

reserve design unintended consequences and the demise of boston s walk zones we show that in the presence of admissions reserves the effect of the precedence order i e the order in which different types of seats are filled is comparable to the effect of adjusting reser

social security and private saving reply i am embarrassed by the programming error that dean leimer and selig lesnoy uncovered but grateful to them for the care with which they repeated my original study feldstein 1974 they set an admirable example of the tradition of replication on which all scientific work ultimately rests as economic research increasingly involves large and complex computer programs to analyze macroeconomic data sets or to simulate models that cannot be solved analytically replication studies like that of leimer and lesnoy social security and private saving new time series evidence in this issue should become increasingly important in their comment leimer and lesnoy also suggest a variety of modifications to the social security wealth variable to incorporate alternative employee perceptions and actuarial assumptions as i explain below i have strong doubts about the appropriateness of these modifications i therefore do not agree with their conclusion that the time series evidence does not support the hypothesis that the introduction of social security has substantially reduced personal saving in the united states more specifically as i show in this reply correcting the computerprogramming error and reestimating the original equation for the original sample period produces results that are not substantially different from the results that were originally published in 1974 the point estimate of the coefficient of social security wealth implies that the level of social security wealth in the final year of the sample 1971 depressed personal saving by an amount equal to 44 percent of the actual personal saving in that year although the estimated coefficient of the social security wealth variable is smaller than in the original version and its standard error larger the conventional statistical test

designing random allocation mechanisms theory and applications randomization is commonplace in everyday resource allocation we generalize the theory of randomized assignment to accommodate multi unit allocations and various real world constraints such as group specific quotas controlled choice in school choice and house allocation and scheduling and curriculum constraints in course allocation we develop new mechanisms that are ex ante efficient and fair in these environments and that incorporate certain non additive substitutable preferences we also develop a utility guarantee technique that limits ex post unfairness in random allocations supplementing the ex ante fairness promoted by randomization this can be applied to multi unit assignment problems and certain two sided matching problems jel c78 d82

uncertain lifetimes and the welfare enhancing properties of annuity markets and social security this paper explores the implications of social security programs and annuity markets through which agents who are characterized by different distributions of length of lifetime share deathrelated risks when annuity markets operate a non discriminatory social security program affects only the intragenerational allocation of resources in the absence of private information regarding individual survival probabilities such a program will lead to a non optimal intragenerational allocation of resources however the presence of adverse selection considerations gives rise to a pareto improving role for a mandatory non discriminatory social security program

a second look at the bangkok land and housing market an earlier paper by the present author published in this journal in 1989 reported on a detailed analysis of the bangkok land and housing market carried out in 1987 88 based on a recent reassessment this paper compares the performance of bangkok s land and housing markets in 1974 84 and 1988 90 the results of the comparative analysis are striking despite rapid increases in land conversion pressure and price increases bangkok s housing developers are still providing considerable amounts of affordable housing unconstrained by zoning they have decentralised development projects and increased project densities dramatically

modularity and greed in double auctions abstract designing double auctions is a complex problem especially when there are restrictions on the sets of buyers and sellers that may trade with one another the goal of this paper is to develop a modular approach to the design of double auctions by relating it to the exhaustively studied problem of designing one sided mechanisms with a single seller or alternatively a single buyer we consider several desirable properties of a double auction feasibility dominant strategy incentive compatibility the still stronger incentive constraints offered by a deferred acceptance implementation exact and approximate welfare maximization and budget balance for each of these properties we identify sufficient conditions on two one sided algorithms one for ranking the buyers one for ranking the sellers and on a method for their composition into trading pairs which guarantee the desired property of the double auction our framework also offers new insights into classic double auction designs such as the vcg and mcafee auctions with unit demand buyers and unit supply sellers

profit maximizing matchmaker abstract this paper considers a resource allocation mechanism that utilizes a profit maximizing auctioneer matchmaker in the kelso crawford 1982 many to one assignment problem we consider general and simple individualized price message spaces for firms reports following milgrom 2010 we show that in the simple message space i the matchmaker s profit is always zero and an acceptable assignment is achieved in every nash equilibrium and ii the sets of stable assignments and strong nash equilibria are equivalent by contrast in the general message space the matchmaker may make a positive profit in a nash equilibrium this shows that restricting message space not only reduces the information requirement but also improves resource allocation

matching with contracts we develop a model of matching with contracts which incorporates as special cases the college admissions problem the kelso crawford labor market matching model and ascending package auctions we introduce a new law of aggregate demand for the case of discrete heterogeneous workers and show that when workers are substitutes this law is satisfied by profit maximizing firms when workers are substitutes and the law is satisfied truthful reporting is a dominant strategy for workers in a worker offering auction matching algorithm we also parameterize a large class of preferences satisfying the two conditions

matching and price competition we develop a model in which firms set impersonal salary levels before matching with workers wages fall relative to any competitive equilibrium while profits rise almost as much implying little inefficiency furthermore the best firms gain the most from the system while wages become compressed in light of our results we discuss the performance of alternative institutions and the recent antitrust case against the national resident matching program

the strategy structure of two sided matching markets we study two sided markets in which agents are buyers and sellers or firms and workers or men and women the agents are to form partnerships which provide them with satisfaction and at the same time make monetary transfers e g salaries or dowries the core of this market game is shown to have a particularly nice structure so that precise answers can be given to questions concerning comparative statics and manipulability the idea of using walrasian equilibrium as a mechanism for making allocations with desirable properties of fairness and efficiency has been studied extensively the scheme involves having agents specify their supply and demand functions the competitive equilibria are then calculated and allocations are made accordingly in general this procedure may run into two difficulties first nonuniqueness if there are several equilibria there may be no fair way to decide which one should be implemented and second manipulability if there is only one equilibrium an informed agent may be able to influence it by suitably falsifying his demand data however as we will show here using the walrasian mechanism does work remarkably well for a certain class of important markets these are the matching markets of our title and they include markets for single items like houses where it is assumed that traders do not wish to acquire more than one item they also include labor markets in which it is desired to match workers with jobs at suitable salaries academic markets in which students are to be assigned to educational institutions marriage markets where men and women are matched through negotiating of dowries it turns out that in these markets both the problems of nonuniqueness and manipulability can be resolved in a

social insurance and consumption an empirical inquiry the main stated purposes of social insurance programs have been the maintenance of consumption by people suffering from misfortunes and the stabilization of employment despite this most recent research on unemployment insurance ui and old age insurance has focused on secondary labor market effects with only a few studies looking at stabilization and none considering effects on consumption in this study we examine how ui will affect the consumption of recipients for some individuals ui will help remove the constraints on consumption during periods of reduced income that arise from insufficient savings and imperfect capital markets while for others the ui benefits merely augment the entire lifetime consumption stream the model enables us to estimate what fractions of the population fall into these two categories if individuals are also constrained in the allocation of their reduction consumption consumption propensities out of ui will differ from those out of nonrecipients income the model is tested on aggregate time series data covering 41 consumption categories for 1959 1978 ii and on over 14 000 individuals from the 1972 73 consumer expenditure survey in both data sets we find no more than half of ui benefits are consumed as if the recipients consumption were constrained during times of unemployment in both samples spending out of ui benefits is disproportionately on luxuries though ui recipients spend greater shares of their income on necessities the results imply that a large part of social insurance payments does not go to prevent serious imbalances in individuals lifetime consumption profiles this abstract was borrowed from another version of this item

recent developments in matching with constraints in an earlier work kamada and kojima 2015 we introduced matching with constraints a two sided matching problem in which the market is subject to feasibility constraints that paper proposed and analyzed a possible solution to this problem and discussed various real market applications of our results the present paper reorganizes some of the findings from our more recent effort based on kamada and kojima 2016a b

uncertain lifetime consumption and dissaving in retirement this paper asks whether the continued accumulation or mild dissaving observed among the retired can be explained by uncertain lifetime in the absence of annuities after an initial period influenced by borrowing constraints under constant relative risk aversion uncertain lifetime depresses consumption by a proportion increasing with age if the elasticity of intertemporal substitution in consumption is small illustrative computations based on actual income and survival data show that plausible elasticities are sufficiently small to give this effect the reduction in consumption is large enough to explain much of the lack of decumulation by the elderly

how to control controlled school choice we characterize choice rules for schools that regard students as substitutes while expressing preferences for a diverse student body the stable or fair assignment of students to schools requires the latter to regard the former as substitutes such a requirement is in conflict with the reality of schools preferences for diversity we show that the conflict can be useful in the sense that certain unique rules emerge from imposing both considerations we also provide welfare comparisons for students when different choice rules are employed

communication and efficiency in auctions abstract we study auctions under restricted communication agents have valuations distributed over an interval but can only report one of a finite number of messages we provide necessary conditions for welfare as well as revenue maximizing auctions in the independent private values case when bidders report simultaneously we also show that the seller who chooses how to allocate a fixed number of messages allocates them evenly over all agents

the price of land for housing in jakarta in spite of its potential value to governments detailed information as to how land prices vary spatially within third world cities is usually lacking this paper discusses the distribution of land prices in jakarta using information provided on a neighbourhood basis by experienced real estate brokers appraised prices were given for different types of residential plot distinguished by tenure and infrastructural provision analysis of the data in jakarta shows the relative importance of infrastructural provision and tenure land title for land prices examination of such data over time makes it possible to test whether and where there has been a spiralling of land prices and in the case of jakarta it is found that recent price increases have been consistently greater in suburban areas and in informal sector plots arising from the massive demand from low income households for affordable housing the paper concludes by drawing out policy implications

equilibria and indivisibilities gross substitutes and complements this paper examines an exchange economy with heterogeneous indivisible objects that can be substitutable or complementary we show that a competitive equilibrium exists in such economies provided that all the objects can be partitioned into two groups and from the viewpoint of each agent objects in the same group are substitutes and objects across the two groups are complements this condition generalizes the well known kelso crawford gross substitutes condition and is called gross substitutes and complements we also provide practical and typical examples from which substitutes and complements are both jointly observed

a leaky bucket in the real world estimating inequality aversion using survey data existing evidence of inequality aversion relies on data from class room experiments where subjects face hypothetical questions this paper estimates the magnitude of inequality aversion using representative survey data with questions related to the real economy situations the respondents face the results reveal that inequality aversion can be measured in a meaningful way using survey data but the magnitudes of the estimates depend dramatically on how inequality aversion is measured no matter how measured the revealed inequality aversion predicts opinions on a wide range of questions related to the welfare state such as the level of taxation tax progressivity and the structure of unemployment benefits