termination of dynamic contracts in an equilibrium labor market model i construct an equilibrium model of the labor market where workers and firms enter into dynamic contracts that can potentially last forever but are subject to optimal terminations upon a termination the firm hires a new worker and the worker who is terminated receives a termination contract from the firm and is then free to go back to the labor market to seek new employment opportunities and enter into new dynamic contracts the model permits only two types of equilibrium terminations that resemble respectively the two kinds of labor market separations that are typically observed in practice involuntary layos and voluntary retirements the model allows simultaneous determination of its equilibrium turnover unemployment and retirement as well as the expected utility of the new labor market entrants

computing multi period information constrained optima this paper presents a detailed theoretical derivation and justification for methods used to compute solutions to a multi period including infinite period continuum agent unobservedeffort economy actual solutions are displayed illustrating cross sectional variability in consumption and labour effort in the population at a point in time and variability for a typical individual over time the optimal tradeoff between insurance and incentives is explored and the issue of excess variability is addressed by consideration of the analogue full information economy and various restricted contracting regimes

aggregate consequences of limited contract enforceability we study a general equilibrium model in which entrepreneurs finance investment with optimal financial contracts because of enforceability problems contracts are constrained efficient we show that limited enforceability amplifies the impact of technological innovations on aggregate output this implies that economies with lower enforceability of contracts are characterized by greater macroeconomic volatility a key assumption for the amplification result is that defaulting entrepreneurs are not excluded from the market

costly monitoring financial intermediation and equilibrium credit rationing abstract this paper establishes a link between equilibrium credit rationing and financial intermediation in a model with asymmetrically informed lenders and borrowers costly monitoring and investment project indivisibilities intermediation is shown to dominate borrowing and lending between individuals and these financial intermediaries exhibit several of the important features of intermediaries as we know them equilibrium interest rates and the aggregate quantity of loans respond quite differently to changes in taste and technology parameters depending on whether or not there is rationing in equilibrium

optimal lending contracts with long run borrowing constraints this paper discusses two variations to the optimal lending contract under asymmetric information studied in clementi and hopenhayn 2006 one variation assumes that the entrepreneur is less patient than the bank and the other assumes the bank has limited commitment the qualitative properties of the two modified contracts are very similar in particular both variations lead to borrowing constraints that are always binding such that the firm is financially constrained throughout its life cycle and subject to a positive probability of being liquidated eventually

optimal multiperiod contracts and the gain from enduring relationships under private information informational asymmetries can play a key role in explaining the existence and nature of multiperiod contracts in an illustrative risk sharing model even relatively short two period contracts can be mutually beneficial if there is private information though one period contracts suffice otherwise further contracts which are pareto optimal relative to the environment and the information structure are defined and partially characterized an example illustrates how otherwise inefficient intertemporal tie ins can be used optimally to mitigate incentive problems the obvious borrowing lending schemes are not private information pareto optimal in these period by period actions are not sufficiently constrained discounting affects the form of the optimal contract but none of these qualitative conclusions

financial intermediation business failures and real business cycles in this paper a general equilibrium business cycle model is construct ed that when subjected to real disturbances mimics observed qualita tive comovements among real output money business failures risk pr emia intermediary loans and prices in contrast monetary disturban ces generate cycles that have several inconsistencies with empirical evidence thus providing support for real business cycle theory at th e expense of monetary theories of the business cycle financial inter mediation arises endogenously in the model and intermediation matters for business cycle behavior a credit supply mechanism acts in tande m with an intertemporal substitution effect in propagating stochastic disturbances copyright 1987 by university of chicago press

capital market imperfections international credit markets and nonconvergence abstract we consider a two country growth model with international capital markets these markets fund capital investment in both countries and operate subject to a costly state verification csv problem investors in each country require some external finance but also provide internal finance which mitigates the csv problem when two identical except for their initial capital stocks economies are closed they necessarily convergemonotonicallyto the same steady state output level unrestricted international financial tradeprecludesotherwise identical economies from converging and poor countries are necessarily net lenders to rich countries oscillation in real activity and international capital flows can occur journal of economic literatureclassification numbers e00 f00 f34 g14

financing development the role of information costs to address how technological progress in nancial intermediation aects the economy a costly state veri cation framework is embedded into the standard growth model the framework has two novel ingredients first rms dier in the risk return combinations that they oer second the e cacy of monitoring depends upon the amount of resources invested in the activity a nancial theory of rm size results undeserving rms are over nanced deserving ones under funded technological advance in intermediation leads to more capital accumulation and a redirection of funds away from unproductive rms toward productive ones quantitative analysis suggests that nance is important for growth

financial market frictions monetary policy and capital accumulation in a small open economy abstract we consider a small open economy with a costly state verification problem and binding reserve requirements the presence of these frictions leads to the existence of two steady states with credit rationing an increase in the money growth rate the world interest rate or reserve requirements raises lowers gdp in the high low activity steady state however sufficiently large increases in money growth or the world interest rate can transform the high activity steady state from a sink to a source the model also delivers prescriptions for restoring the stability of this steady state in such an eventuality journal of economic literatureclassification numbers e5 f4

growth and risk sharing with private information abstract we examine the impact of incomplete risk sharing on growth and welfare the source of market incompleteness in our economy is private information a household s idiosyncratic productivity shock is not observable by others risk sharing between households occurs through long term contracts with intermediaries we find that incomplete risk sharing tends to reduce the rate of growth relative to the complete risk sharing benchmark numerical examples indicate that the welfare cost and the growth effect of private information are small

efficiency and equality in a simple model of efficient unemployment insurance abstract this paper describes the efficient allocation of consumption and work effort in an economy in which workers face idiosyncratic employment risk and considerations of moral hazard prevent full insurance we impose a lower bound on the expected discounted utility that can be assigned to any agent from any date onward and show with this feature added that the efficient unemployment insurance scheme induces an invariant cross sectional distribution of individual entitlements to utility the paper thus provides a simple prototype model suited to the study of the normative question what is the trade off between equality and efficiency in resource allocation journal of economic literature classification numbers d31 d63 d82 j65

speculation and risk sharing with new financial assets while the traditional view of nancial innovation emphasizes the risk sharing role of new nancial assets belief disagreements about these assets naturally lead to speculation which represents a powerful economic force in the opposite direction this paper investigates the eect of nancial innovation on portfolio risks in an economy when both the risk sharing and the speculation forces are present financial assets provide hedging services but they are also subject to speculation because traders do not necessarily agree about their payos i de ne the average variance of traders net worths as a measure of portfolio risks for this economy and i decompose it into two components the uninsurable variance de ned as the average variance that would obtain if there were no belief disagreements and the speculative variance de ned as the residual variance that results from speculative trades based on belief disagreements financial innovation always decreases the uninsurable variance because new assets increase the possibilities for risk sharing my main result shows that nancial innovation also always increases the speculative variance this is true even if traders completely agree about the payos of new assets the intuition behind this result is the hedge more bet more eect traders use new assets to hedge their bets on existing assets which in turn enables them to place larger bets and take on greater risks my second set of results concern endogenous nancial innovation when belief disagreements are su ciently large a pro t seeking market maker introduces assets that maximize the average variance among all possible choices completely disregarding the risk sharing motive for nancial innovation my third set of results concern a calibration of the model in the context of the gdp indexed assets proposed by athanasoulis and shiller 2001 when traders have reasonable amounts of belief disagreements these assets would have the unintended consequence of increasing their consumption risks

dynamic credit relationships in general equilibrium abstract we construct a general equilibrium model with private information in which borrowers and lenders enter into long term dynamic credit relationships each new generation of ex ante identical individuals is divided in equilibrium into workers and entrepreneurs workers save through financial intermediaries in the form of interest bearing deposits and supply labor to entrepreneurs in a competitive labor market entrepreneurs borrow from financial intermediaries to finance projects which produce privately observed sequences of random returns each financial intermediary holds deposits from a large number of workers and operates a portfolio of dynamic contracts with different credit positions we calibrate the model to the u s economy and find that dynamic contracting is very effective at mitigating the effects of private information moreover restricting borrowers and lenders to use static one period contracts with a costly monitoring technology has adverse effects both on the level of aggregate economic activity and on individual welfare unless monitoring costs are very small finally the optimal provision of intertemporal incentives leads to increasing consumption inequality over time within generational cohorts as in u s data

income and wealth heterogeneity in the macroeconomy how do movements in the distribution of income and wealth affect the macroeconomy we analyze this question using a calibrated version of the stochastic growth model with partially uninsurable idiosyncratic risk and movements in aggregate productivity our main finding is that in the stationary stochastic equilibrium the behavior of the macroeconomic aggregates can be almost perfectly described using only the mean of the wealth distribution this result is robust to substantial changes in both parameter values and model specification our benchmark model whose only difference from the representative agent framework is the existence of uninsurable idiosyncratic risk displays far less cross sectional dispersion and skewness in wealth than u s data however an extension that relies on a small amount of heterogeneity in thrift does succeed in replicating the key features of the wealth data furthermore this extension features aggregate time series that depart significantly from permanent income behavior

targeted export subsidies as an exercise of monopoly power a country with monopoly power in its export good normally benefits from an export tax however if it exports to two countries and the tax on exports to one is suboptimal then it may be best to subsidize exports to the other this is more likely the smaller is the import demand elasticity in the country being taxed suboptimally and the larger the elasticity in the other it is also more likely the larger are exports to the first and the smaller are exports to the other finally it is more likely the less elastic is home export supply

costly monitoring loan contracts and equilibrium credit rationing this paper develops a model with asymmetrically informed agents and costly monitoring of loan contracts where an equilibrium can exhibit credit rationing borrowers are identical ex ante but some receive loans and others do not in contrast to existing credit rationing theories rationing does not occur here due to inflexible prices adverse selection or moral hazard optimizing behaviour produces a standard debt contract in equilibrium the aggregate quantity of loans and equilibrium interest rates respond differently depending on whether there is rationing in equilibrium

relationship lending and the transmission of monetary policy abstract repeated interactions allow lenders to uncover private information about their clients decreasing the informational asymmetry between a borrower and his lender but introducing one between the lender and competing financiers this paper constructs a credit based model of production to analyze how learning through lending relationships affects monetary transmission i examine how monetary policy changes the incentives of borrowers and lenders to engage in relationship lending and how these changes then shape the response of aggregate output the results demonstrate that relationship lending prevails in equilibrium smoothes the steady state output profile and induces less volatile responses to certain monetary shocks

on efficient distribution with private information this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with many consumers each of whom is subject to private idiosyncratic taste shocks we propose a recursive method for finding feasible allocations that are incentivecompatible and that are pareto optimal within this set the method is applied to several parametric examples we find that in an efficient allocation the degree of inequality continually increases with a diminishing fraction of the population receiving an increasing fraction of the resources we discuss the extent to which these allocations can be decentralized via market arrangements this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with private information the economy we study has a constant endowment flow of a single non storable consumption good which is to be allocated each period among a large number of consumers each period these consumers experience unpredictable idiosyncratic privately observed taste shocks affecting their marginal utility of current consumption efficiency dictates that more resources be allocated to those consumers who in any given period have a high marginal utility of current consumption

financial capacity and output fluctuations in an economy with multi period financial relationships this paper motivates a financial propagation mechanism in the context of an intertemporal production economy with asymmetric information and with borrowers and lenders who enter multi period financial relationships a key feature is that aggregate output and borrowers financial capacity the maximum overhang of past debt they may feasibly carry are determined jointly much in the spirit of gurley and shaw 1955 expectations of future economic conditions govern financial capacity which in turn may constrain current production especially in bad times a small but persistent shift in aggregate conditions may have a large impact on financial capacity making the framework capable of motivating large endogenous fluctuations in financial constraints understanding how small disturbances can induce large output fluctuations is an on going quest in macroeconomics this paper develops a simple framework in which shifts in aggregate economic fundamentals are amplified through their impact on financial conditions a distinguishing feature is that output and borrowers financial capacity the maximum overhang of past debt they may feasibly carry are determined jointly much in the spirit of gurley and shaw 1955 expectations of future economic conditions govern financial capacity and financial capacity may constrain current production especially in bad times a number of recent papers have resurrected the view that financial factors may play a part in propagating business fluctuations the underlying theories exploit the idea that with asymmetric information between borrowers and lenders agency costs may drive the price of uncollateralized external funds above the price of internal funds in this kind of setting a borrower s financial position is a key determinant of the terms of credit she faces in the aggregate swings in borrower balance sheets over the cycle amplify fluctuations in investment and output essentially by inducing counter cyclical movements in the required premium for external finance this simple mechanism is broadly consistent with informal descriptions of how financial and real variables interacted in the great depression bernanke 1983 and in the postwar business cycles eckstein and sinai 1986 in addition numerous recent panel data studies beginning with fazzari hubbard and peterson 1988 support the notion of a financial investment accelerator mechanism

efficient allocations with hidden income and hidden storage we consider an environment in which individuals receive income shocks that are unobservable to others and can privately store resources we provide a simple characterization of the unique efficient allocation of consumption in cases in which the rate of return on storage is sufficiently high or alternatively in which the worst possible outcome is sufficiently dire we show that unlike in environments without unobservable storage the symmetric efficient allocation of consumption is decentralizable through a competitive asset market in which individuals trade riskfree bonds among themselves in this paper we consider an environment in which individuals have random income and can accumulate assets through a storage technology their income realizations and their asset position are private information given these informational frictions we provide a simple characterization of the unique efficient allocation of consumption in cases in which the rate of return on storage is sufficiently high or alternatively in which the worst possible outcome is sufficiently dire we show that the symmetric efficient allocation of consumption is decentralizable through a competitive asset market in which individuals trade risk free bonds among themselves there is a large prior literature which examines the characteristics of efficient risksharing in dynamic settings in the presence of private information unlike our paper this literature generally finds that efficient allocations do not coincide with the equilibrium allocations of any economy with a competitive bond market see atkeson and lucas 1992 in particular the key difference between our paper and these preceding ones is that the earlier literature assumes either that agents cannot accumulate resources over time or that if they can this accumulation is observable in contrast we assume that both agents incomes and their stored resources are private information it is this combination of assumptions that leads to our result our findings are reminiscent of allen s 1985 he considers a dynamic principalagent relationship in which the agent is risk averse and has hidden stochastic income the

dynamic insurance with private information and balanced budgets this paper studies a dynamic insurance problem with bilateral asymmetric information and balanced budgets there are two infinitely lived agents in our model both risk averse and each has an i i d random endowment stream which is unobservable to the other in each period each agent must have a non negative consumption and together they must consume the entire aggregate endowment dynamic incentive compatibility in the nash sense is defined we give sufficient and necessary conditions for the existence of a constrained efficient contract we show that a constrained efficient contract can be characterized in a bellman equation we demonstrate that the long run distribution of expected utilities of each agent is not degenerate we also develop an algorithm for computing the efficient contract and in a numerical example we find that the consumption processes of the agents form stationary markov chains

consumption and risk sharing over the life cycle a striking feature of u s data on income and consumption is that inequality increases with age this paper asks if individual specific earnings risk can provide a coherent explanation we find that it can we construct an overlapping generations general equilibrium model in which households face uninsurable earnings shocks over the course of their lifetimes earnings inequality is exogenous and is calibrated to match data from the u s panel study on income dynamics consumption inequality is endogenous and matches well data from the u s consumer expenditure survey the total risk households face is decomposed into that realized before entering the labor market and that realized throughout the working years in welfare terms the latter is found to be more important than the former

life cycle economies and aggregate fluctuations do the implications for business cycle issues change when we switch from studying infinitely lived representative agent models to more sophisticated demographic structures with finitely lived agents this article addresses that question by using a large overlapping generations model that is calibrated to u s demographic properties microeconomic evidence and national income and product accounts the finding is that the answers obtained are basically the same for the two kinds of models the article also explores the relative volatility of hours across age groups an issue that cannot be addressed by using the infinitely lived representative agent abstraction

income fluctuation and asymmetric information an example of a repeated principal agent problem we examine a simple repeated principal agent model with discounting there are a risk averse borrower with an unobservable random income and a risk neutral lender the efficient contract is characterized it tends to the first best constant consumption contract as the discount factor tends to one and the time horizon extends to infinity if the time horizon is infinite and the contract is legally enforceable the borrower s utility becomes arbitrarily negative with probability one if the borrower has constant absolute risk aversion consumption is transferred between any two states at a constant interest rate which is less than the rate of time preference

on repeated moral hazard with discounting in this paper we analyze optimal contracts in an infinitely repeated agency model in which both the principal and agent discount the future we show that there is a stationary representation of the optimal contract when the agent s conditional discounted expected utility is used as a state variable this representation reduces the multi period problem to a static variational problem which can be analyzed using standard variational techniques this reduction is used to obtain several properties of the contract

risk bearing and the theory of income distribution this paper develops the stochastic theory of distribution with a dynamic model which focuses on the role of incomplete insurance in generating inequality unlike previous work our approach takes explicit account of the reason for market incompleteness in modeling agents behaviour in particular the amount of risk borne is endogenous using a model of growth with altruism in which agents are risk averse and there is moral hazard we show that lineage wealth follows a markov process which converges globally to an ergodic distribution this also represents the long run population distribution of wealth we discuss the role of particular assumptions such as availability of production loans and unboundedness of utility in yielding the qualitative properties of the distribution of wealth the choice of occupation and the prevention of poverty traps