time consistent public policy in this paper we study how a benevolent government that cannot commit to future policy should trade off the costs and benefits of public expenditure we characterize and solve for markov perfect equilibria of the dynamic game between successive governments the characterization consists of an inter temporal first order condition a generalized euler equation for the government and we use it both to gain insight into the nature of the equilibrium and as a basis for computations for a calibrated economy we find that when the only tax base available to the government is capital income an inelastic source of funds at any point in time the government still refrains from taxing at confiscatory rates we also find that when the only tax base is labour income the markov equilibrium features less public expenditure and lower tax rates than the ramsey equilibrium

politics and efficiency of separating capital and ordinary government budgets we analyze a golden rule that separates capital and ordinary account budgets and allows a government to finance only capital items with debt many national governments followed this rule in the eighteenth and nineteenth centuries and most u s states do today we study an overlapping generations economy where majorities choose durable and nondurable public goods in each period when demographics imply even moderate departures from ricardian equivalence the golden rule substantially improves efficiency examples calibrated to u s demographics show greater improvements at the state level or with nineteenth century demographics than under current national demographics

bailouts time inconsistency and optimal regulation a macroeconomic view a common view is that bailouts of firms by governments are needed to cure inefficiencies in private markets we propose an alternative view even when private markets are efficient costly bankruptcies will occur and benevolent governments without commitment will bail out firms to avoid bankruptcy costs bailouts then introduce inefficiencies where none had existed although granting the government orderly resolution powers which allow it to rewrite private contracts improves on bailout outcomes regulating leverage and taxing size is needed to achieve the relevant constrained efficient outcome the sustainably efficient outcome this outcome respects governments incentives to intervene when they lack commitment

price formation in a matching market with targeted offers abstract we model a market where the surpluses from seller buyer matches are heterogeneous but common knowledge price setting is synchronous with search buyers simultaneously make one personalized offer each to the seller of their choice with impatient players efficient coordination is not possible and both temporary and permanent mismatches occur nonetheless for patient players efficient matching with monopsony wages is an equilibrium the setting is inspired by a labor market for highly skilled workers such as the academic job market but it can be easily adapted to for example the housing market or internet advertising auctions

is a policy of free movement of workers sustainable this paper studies the costs and benets of the adoption of the policy of free movement for workers for the countries to agree on uncontrolled movement of workers the short run costs must be outweighed by the long term benets that result from better labor market exibility and income smoothing we show that such policies are less likely to be adopted when workers are impatient and less risk averse workers when production technologies display decreasing returns and when countries trade a share of their products

time consistent monetary policy with endogenous price rigidity abstract i characterize time consistent equilibrium in an economy with price rigidity and an optimizing monetary authority operating under discretion firms have the option to increase their frequency of price change at a cost in response to higher inflation previous studies which assume a constant degree of price rigidity across inflation regimes find two time consistent equilibria one with low inflation the other with high inflation in contrast when price rigidity is endogenous the high inflation equilibrium ceases to exist hence time consistent equilibrium is unique this result depends on two features of the analysis 1 a plausible quantitative specification of the fixed cost of price change and 2 the presence of an arbitrarily small cost of inflation that is independent of price rigidity

decentralized matching markets with endogenous salaries abstract in a shapley shubik assignment problem with a supermodular output matrix we consider games in which each firm makes a take it or leave it salary offer to one applicant and a match is made only when the offer is accepted by her we consider both one shot and multistage games in either game we show that there can be many equilibrium salary vectors which are higher or lower than the minimum competitive salary vector if we exclude artificial equilibria applicants equilibrium salary vectors are bounded above by the minimal competitive salary vector while firms equilibrium payoff vectors are bounded below by the payoff vector under the minimum competitive salary vector this suggests that adopting the minimum competitive salary vector as the equilibrium outcome in decentralized markets does not have a strong justification

pareto efficient income taxation with stochastic abilities abstract this paper studies pareto efficient income taxation in an economy with finitely lived individuals whose income generating abilities evolve according to a two state markov process the study yields three main results first when individuals are risk neutral in any period the only individuals whose earnings are distorted are those who currently are and have always been low ability in addition the degree to which these perpetual low ability types have their earnings distorted decreases over time converging to zero if the time horizon is long enough second the earnings distortions are continuous with respect to the degree of risk aversion at the risk neutral solution third pareto efficient income tax systems can be time consistent even when the degree of correlation in ability types is large the condition for time consistency suggests a novel theoretical reason why the classic equity efficiency trade off may be steeper in a dynamic environment than previously thought

banking panics and policy responses we study how banking panics unfold in av ersion of the diamond and dybvig 1983 model with limited commitment as is well known the banking authority could eliminate the possibility of a run on the banking system by committing to suspend payments to depositors if a run were to start once a run is under way however the banking authority will choose to reschedule rather than suspend payments we construct equilibria in which depositors run on the banking system with positive probability and we show that an equilibrium bank run in this setting is necessarily partial with only some depositors participating we also show that a run naturally occurs in waves with each wave of withdrawals prompting a further policy response from the banking authority the number of waves that occur in equilibrium is stochastic and can be arbitrarily large

time consistent public expenditures in this paper we study the optimal choice of public expenditures when there is no way of committing to future policy and reputational mechanisms are not operative this amounts to conflning our attention to markov equilibria the environment is a neoclassical growth model where consumers derive utility from a public good this environment gives rise to a dynamic game between successive governments and the private sector and this game is made interesting by the presence of a state variable the capital stock we characterize equilibria in terms of an intertemporal flrst order condition a generalized euler equation gee for the government and we use this condition both to gain insight into the nature of the equilibrium and as a basis for computation the gee reveals how the government optimally trades ofi tax wedges over time it also allows us to discuss in what sense a current government may be strategically in uencing future governments in their taxation decisions for a calibrated economy we flnd that when the tax base available to the government is capital income an inelastic source of funds at any moment in time the government still refrains from taxing at high rates in order to smooth distortions over time as a result the economy is far from the mix of public and private goods that would be optimal in a static context in return the savings distortion is not very severe and the capital stock is quite high

matching with contracts comment the theory of two sided matching markets has interested researchers for its theoretical appeal and its relevance to the design of real world institutions the medical residency matching mecha nism in the united states the national resident matching program nrmp and student assign ment systems in new york city and boston are important mechanisms designed by economists using the theory 1 hatfield and paul r milgrom 2005 present a unified framework of matching with contracts which includes the two sided matching and package auction models as well as a simplified version of a labor market model of alexander kelso and vincent p crawford 1982 as special cases they introduce the substitutes condition of contracts which is an adaptation of the substitutability condition in the matching literature roth and marilda a oliveira sotomayor 1990 to matching with contracts they show that there exists a stable allocation if contracts are substitutes for hospitals and that a number of other results in matching generalize to problems with contracts they further claim that the substitutes condition on individual hospitals prefer ences is necessary to guarantee the existence of a stable allocation for all possible singleton preferences of others that is if contracts are not substitutes for a hospital then there exists a preference profile of other hospitals with single job openings and doctors such that there exists no stable allocation we show that this last claim of hatfield and milgrom 2005 does not hold in general the counterexample we present involves a hospital which has two different kinds of positions and the preferences of the hospital are a combination of preferences of these two positions while the substitutes condition does not hold for that hospital we adopt a technique developed by bettina klaus and flip klijn 2005 and show that there exists a stable allocation we then present the weak substitutes condition which we show is necessary to guarantee existence of stable allocations the modified result we present as well as the original contribu tion of hatfield and milgrom 2005 suggest a connection between the substitutes condition and stability 2

delegation time inconsistency and sustainable equilibrium this paper analyzes the effectiveness of delegation in solving the time inconsistency problem of monetary policy using a microfounded general equilibrium model where delegation and reappointment are explicitly included into the government s strategy the method of chari and kehoe 1990 sustainable plans journal of political economy 98 4 783 802 is applied to characterize the entire set of sustainable outcomes countering mccallum s 1995 two fallacies concerning central bank independence american economic review 85 2 207 211 second fallacy delegation is able to eliminate the time inconsistency problem with the commitment policy being sustained under discretion for any intertemporal discount rate

international interdependencies in fiscal stabilization policies abstract trade links imply that business cycle fluctuations are transmitted among trade partners to the extent that fiscal policy can mitigate business cycle fluctuations international interdependencies in stabilization policies arise we analyse in a two country general equilibrium model the role of fiscal policy in mitigating risk or providing implicit insurance in the presence of capital market imperfections and adjustment failures rigid wages it is shown that there is a welfare case for an active stabilization policy and that it is larger in the presence of adjustment failures rigid wages non cooperative policy decisions imply inefficiencies in fiscal stabilization policies which in the case of flexible wages may imply too much stabilization whereas stabilization is always insufficient in the case of rigid wages

imperfect competition in two sided matching markets abstract this paper considers a simple equilibrium model of an imperfectly competitive two sided matching market firms and workers may have heterogeneous preferences over matches on the other side and the model allows for both uniform and personalized wages or contracts to make the model tractable i use the azevedo and leshno 2013 framework in which a finite number of firms is matched to a continuum of workers in equilibrium even if wages are exogenous and fixed firms have incentives to strategically reduce their capacity to increase the quality of their worker pool the intensity of incentives to reduce capacity is given by a simple formula analogous to the classic cournot model but depends on different moments of the distribution of preferences i compare markets with uniform and personalized wages for fixed quantities markets with personalized wages always yield higher efficiency than markets with uniform wages but may be less efficient if firms reduce capacity to avoid bidding too much for star workers

an analysis of mortgage contracting prepayment penalties and the due on sale clause the due on sale clause contained in most conventional home mortgage contracts is equivalent to a prepayment penalty equal to the difference between the face value and market value of the loan we analyze a bilateral game with asymmetric information and show that the bank demands the full penalty unless the market value of the loan is sufficiently low in that case the bank demands a prepayment penalty which is independent of the market value of the loan in order to induce additional prepayments we also demonstrate by a risk sharing argument that the due on sale clause is optimal in some settings even though it eliminates some beneficial home sales almost all conventional fixed rate home mortgage contracts written in the last decade contain a due on sale clause which gives the lender the contractual right to declare the total indebtedness due immediately if the mortgaged property is transferred as mortgage rates rise lending institutions suffer capital losses on fixed rate mortgage loans while borrowers earn capital gains equal to the difference between the face value and market value of their loans the due onsale clause gives the lending institution the right to demand the borrower s capital gain as a prepayment penalty in order to increase the probability of prepayment it can be optimal for the bank to accept a partial settlement in this paper we analyze the bank s strategy for setting the prepayment penalty it demands under the due on sale clause and examine the optimality of the clause the model we develop also applies to other types of prepayment penalties i e loan covenants which require payment of a premium over market value in order to extinguish

sustaining policy cooperation between economies of different size abstract i consider an example of a two country model featuring national heterogeneity and demonstrate that heterogeneity plays an important role for the countries gains from international policy cooperation and just as important for the incentives to break the cooperative agreement i find that national heterogeneity unambiguously reduces trigger strategies support for policy cooperation in other words the more countries differ the harder it is to sustain policy cooperation

time consistent control in non linear models abstract the paper shows how to use optimal control to compute optimal time consistent markovian government policies in nonlinear dynamic general equilibrium models it extends cohen and michel s 1988 results for the linear quadratic case the method involves replacing private agents costate variables with flexible functions of current state variables in the government s maximization problem the functions hold in equilibrium to an arbitrarily close approximation they can be found numerically by perturbation or projection methods a stochastic model of optimal public spending illustrates the technique

optimal fiscal and monetary policy in an economy without capital abstract this paper is concerned with the structure and time consistency of optimal fiscal and monetary policy in an economy without capital in a dynamic context optimal taxation means distributing tax distortions over time in a welfare maximizing way for a barter economy our main finding is that with debt commitments of sufficiently rich maturity structure an optimal policy if one exists is time consistent in a monetary economy the idea of optimal taxation must be broadened to include an inflation tax and we find that time consistency does not carry over an optimal inflation tax requires commitment by rules in a sense that has no counterpart in the dynamic theory of ordinary excise taxes the reason time consistency fails in a monetary economy is that nominal assets should from a welfare maximizing point of view always be taxed away via an immediate inflation in a kind of capital levy this emerges as a new possibility when money is introduced into an economy without capital

international coordination of fiscal policy in limiting economies we examine the limiting behavior of cooperative and noncooperative fiscal policies as countries market power goes to zero we show that these policies converge if countries raise revenues through lump sum taxation however if there are unremovable domestic distortions such as distorting taxes there can be gains to coordination even when a single country s policy cannot affect world prices these results differ from the received wisdom in the optimal tariff literature the key distinction is that contrary to the tariff literature the spending decisions of governments are explicitly modeled

time inconsistency and free riding in a monetary union in monetary unions a time inconsistency problem in monetary policy leads to a novel type of free rider problem in the setting of non monetary policies the free rider problem leads union members to pursue lax non monetary policies that induce the monetary authority to generate high inflation free riding can be mitigated by imposing constraints on non monetary policies without a time inconsistency problem the union has no free rider problem then constraints on non monetary policies are unnecessary and possibly harmful this theory is here detailed and applied to several non monetary policies labor market policy fiscal policy and bank regulation

optimal fiscal policy in open economies with labour market distortions abstract we set up a general equilibrium model with unemployment owing to distortions in the labour market it is shown that a public expansion financed by a distortionary income tax may give rise to a decrease in unemployment even if public goods are pure waste such an expansion may give rise to an increase in welfare if it is associated with a decrease in unemployment since part of the gain from a fiscal expansion is achieved at the expense of welfare in other countries non cooperative policies tend to be too expansionary

intangible investment and ramsey capital taxation the standard analysis of optimal fiscal policy aggregates different types of assets into a unique capital good and all types of capital taxes into a unique capital tax this paper considers a disaggregated framework an economy with corporate and dividend taxes where firms invest in both tangible and intangible assets which can be expensed or sweat in our setup firms can always respond to changes in the timing of taxation we find that the optimal long run policy features zero corporate taxes and positive dividend taxes with labor and dividend taxes being identical moreover the initial capital levy is relatively small

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

commitment in utility regulation a model of reputation and policy applications abstract this paper builds a dynamic model of utility regulation where a government cannot commit to a time inconsistent policy of not expropriating investment by allowing the government s type to change over time i explore how reputation concerns may generate partial commitment restricting attention to equilibria that are strongly renegotiation proof i show that there is a unique perfect bayesian equilibrium this contains episodes of investment and good behaviour followed by periods of expropriation and non investment i then apply the model to consider how the power of the incentive scheme and decentralization may influence the properties of this equilibrium in the case of the power of incentives the model suggests that price caps may worsen commitment in developing countries but not in developed ones similarly the model suggests that decentralisation is likely to have a significant effect on commitment but that this effect will depend on the general ability of the government to commit overall we conclude that the effect of such policies on commitment will be different across countries depending on the institutional environment

intertemporal cournot and walras equilibria an illustration in an intertemporal general equilibrium framework we compare a cournot equilibrium to the walras equilibrium the cournot agents trade and invest less than the walras agents this generates an inefficiency that does not vanish as the number of cournot agents tends to infinity a larger number of strategic cournot agents implies that the amount of trade relative to their aggregate consumption increases i e it moves towards the walrasian amount but their investment relative to the stock decreases i e it moves away from the walrasian amount s il y avait 3 4 n producteurs en concurrence la valeur de

matching and price competition comment the theory of two sided matching markets has interested researchers for its theoretical appeal and relevance to real life applications the matching of medical residents and hospitals in the united states has been studied extensively by alvin e roth 1984 and others the national resident matching program nrmp the matching authority in the us hospital resident matching market runs a centralized matching mechanism that is a variant of the deferred acceptance algorithm of david gale and lloyd s shapley 1962 redesigned by roth and elliott peranson 1999 a recent antitrust case against the nrmp charged that the centralized matching mechanism suppressed wages of residents although the lawsuit itself was dismissed it sparked discussion about the effect of centralized matching on wages and efficiency jeremy bulow and jonathan levin 2006 bl henceforth investigate a matching market with price competition where each firm can hire only one worker and show that a the average wage is lower b profit of each firm is higher c wages are more compressed and d the resulting matching is slightly less efficient in the presence of the matching mechanism than in any competitive equilibrium although bl declare we have chosen our assumptions for analytical simplicity and transparency not as the most realistic possible model of the residency match 654 these results were often interpreted as an argument against the nrmp and led to discussion about potential changes of the matching mechanism vincent p crawford forthcoming for instance proposes the flexible salary match in which hospitals are allowed to indicate several levels of possible wages and medical students are allowed to express preferences over pairs of hospitals and wages we show that conclusions a and b above do not necessarily hold when firms may hire more than one worker and the number of workers in different firms are different more specifically we present an example with multiple positions in which the average worker wage is higher in the equilibrium with the matching mechanism than in a competitive equilibrium and profit of each firm is lower in the equilibrium with the matching mechanism than in a competitive equilibrium our findings may explain why some of the results of bl disagree with empirical findings of muriel niederle and roth 2003 2004 who find little or no effect of the centralized matching on wages in some medical matching markets in the united states note that different firms hire different numbers of workers in many labor markets like the nrmp there are other reasons why the conclusions and policy implications of bl may not be applicable to markets like the nrmp for example a competitive equilibrium may not be a

optimal monetary policies and policy interdependence in the world economy the literature on strategic policy interactions has focused on the implications of alternative strategic policy interactions cooperative versus noncooperative for equilibrium macroeconomic policies given the state of the world economy this paper asks how changes in world economic conditions alter equilibrium policies given the nature of policy interdependence among nations the paper considers a world economy comprised of two countries operating under a system of flexible exchange rates both governments act noncooperatively and choose the rate of growth of their money supply so as to maximize the utility of their country s residents given the rate of growth of the other country s money supply the resulting nash equilibrium rates of growth of the home and foreign money supplies are determined and the dependence of international differences in money growth and inflation rates on international differences in technology jel e52 e60 f41 f42 the international transmission of monetary and fiscal policies has been studied a great deal by economists however policy interdependence how one country s policies depend on the policies enacted by other countries has only recently begun to be explored hamada s 1976 paper was one of the first major contributions in this regard hamada considered a world economy comprised of n countries operating under a fixed exchange rate system in which policymakers set domestic credit growth so as to maximize an objective function depending on inflation and the rate of accumulation of international reserves using this framework hamada demonstrated that in equilibrium optimal domestic credit policies are generally not pareto efficient when they are chosen noncooperatively but are pareto efficient when they are set cooperatively in subsequent work hamada 1979 1985 has elaborated on this and various other aspects of cooperative and noncooperative monetary policies under both fixed and flexible exchange rates many others have followed hamada s lead by comparing the properties of cooperative and noncooperative monetary policies eichengreen 1985 for instance considers discount rates as the instrument of monetary policy and examines issues of leadership and cooperation during the interwar years under the gold standard oudiz and sachs 1985 have used simulation methods to

endogenous trade policy and the gains from international financial markets abstract this paper examines the interaction between international financial markets and trade policy when trade policy is endogenous there is a secondary gain from opening up financial markets in addition to the direct risk sharing benefits by breaking the direct link between the terms of trade and welfare international portfolio diversification can allow for a lower level of trade protection in a tariff game between governments we apply the model to an estimation of the welfare gains from international financial markets our results show that these indirect trade gains from financial markets are likely to be much larger than the direct risk sharing gains in the tariff game with financial markets however there are multiple equilibria while one equilibrium allows for complete diversification and complete free trade there are other equilibria in which there is limited diversification and a high level of average protection

capital taxation under political constraints this paper studies optimal dynamic tax policy under the threat of political reform a policy will be reformed ex post if a large enough coalition of citizens supports reform thus sustainable policies are those that will continue to attract enough political support in the future we find that optimal marginal capital taxes are either progressive or u shaped so that savings are subsidized for the poor and or the middle class but are taxed for the rich u shaped capital taxes always emerge when individuals political behavior is purely determined by economic motives

sequential equilibria in a ramsey tax model this paper presents a full characterization of the equilibrium value set of a ramsey tax model more generally it develops a dynamic programming method for a class of policy games between the government and a continuum of households by selectively incorporating euler conditions into a strategic dynamic programming framework we wed two technologies that are usually considered competing alternatives resulting in a substantial simplification of the problem

intertemporal distortions in the second best we consider a very general class of public nance problems that encompasses ramsey models of optimal taxation as well as economies with limited commitment private information and political economy frictions we identify a su cient condition to rule out permanent intertemporal distortions at the optimum if there exists an admissible allocation that converges to the rst best steady state then all intertemporal distortions are temporary in the second best we analyze a series of applications to illustrate the signi cance of this result

on the need for fiscal constraints in a monetary union the desirability of fiscal constraints in monetary unions depends critically on whether the monetary authority can commit to following its policies if it can commit then debt constraints can only impose costs if it cannot commit then fiscal policy has a free rider problem and debt constraints may be desirable this type of free rider problem is new and arises only because of a time inconsistency problem

fixed versus flexible exchange rates which provides more fiscal discipline abstract conventional wisdom holds that fixed rates provide more fiscal discipline than do flexible rates in this paper we show that this wisdom need not hold in a standard model in which fiscal policy is endogenously determined by a maximizing fiscal authority the claim that fixed rates induce more discipline stresses that sustained adoption of lax fiscal policies must eventually lead to an exhaustion of reserves and thus to a politically costly collapse of the peg hence under fixed rates bad behavior today leads to punishment tomorrow under flexible rates bad behavior has costs as well the difference is in the intertemporal distribution of these costs flexible rates allow the effects of unsound fiscal policies to manifest themselves immediately through movements in the exchange rate hence bad behavior today leads to punishment today if fiscal authorities are impatient flexible rates by forcing the costs to be paid up front provide more fiscal discipline and higher welfare for the representative private agent the recent experience of sub saharan countries supplies evidence that matches the predictions of the model

monetary conservatism and fiscal policy abstract does an inflation conservative central bank a la rogoff 1985 remain desirable in a setting with endogenous fiscal policy to provide an answer we study monetary and fiscal policy games without commitment in a dynamic stochastic sticky price economy with monopolistic distortions monetary policy determines nominal interest rates and fiscal policy provides public goods generating private utility we find that lack of fiscal commitment gives rise to excessive public spending the optimal inflation rate internalizing this distortion is positive but lack of monetary commitment generates too much inflation a conservative monetary authority thus remains desirable when fiscal policy is determined before monetary policy each period the monetary authority should focus exclusively on stabilizing inflation monetary conservatism then eliminates the steady state biases associated with lack of monetary and fiscal commitment and leads to stabilization policy that is close to optimal

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

an empirical model of the medical match abstract this paper develops a framework for estimating preferences in a many to one matching market using only observed matches i use pairwise stability and a vertical preference restriction on one side to identify preferences on both sides of the market counterfactual simulations are used to analyze the antitrust allegation that the centralized medical residency match is responsible for salary depression due to residents willingness to pay for desirable programs and capacity constraints salaries in any competitive equilibrium would remain on average at least 23 000 below the marginal product of labor therefore the match is not the likely cause of low salaries jel c78 i11 j31 j44 k21 l44

the international ramifications of tax reforms supply side economics in a global economy this paper studies tax reforms in a dynamic model of a global economy calibrated to current u s and european tax policies world capital markets add consumption smoothing and income redistribution effects that alter closed economy predictions in the absence of taxes on foreign interest welfare gains of eliminating u s income taxes are enlarged by up to 34 percent at the expense of european losses caused by transitional declines in consumption and leisure and a permanent capital outflow in contrast if foreign interest is taxed the same tax reform reduces u s welfare 0 7 percent and increases european welfare 1 8 percent copyright 1998 by american economic association