constrained efficiency in the neoclassical growth model with uninsurable idiosyncratic shocks we investigate the welfare properties of the one sector neoclassical growth model with uninsurable idiosyncratic shocks we focus on the notion of constrained efficiency used in the general equilibrium literature our characterization of constrained efficiency uses the first order condition of a constrained planner s problem this condition highlights the margins of relevance for whether capital is too high or too low the factor composition of income of the consumption poor using three calibrations commonly considered in the literature we illustrate that there can be either over or underaccumulation of capital in steady state and that the constrained optimum may or may not be consistent with a nondegenerate long run distribution of wealth for the calibration that roughly matches the income and wealth distribution the constrained inefficiency of the market outcome is rather striking it has much too low a steady state capital stock

should capital be taxed abstract we design an infinite horizon heterogeneous agents and incomplete markets model to demonstrate analytically that in the absence of any redistributional effects of government policies optimal capital tax is zero despite capital overaccumulation under precautionary savings and borrowing constraints our result indicates that in the long run public debt is a better tool than capital taxation to restore aggregate productive efficiency

optimal growth with many consumers abstract a method is described for constructing all pareto optimal allocations for a dynamic economy with many heterogeneous consumers under certainty in which both the technology and consumer preferences are recursive but preferences need not be additively separable over time optimal perfect foresight competitive equilibrium allocations are obtained through the study of a dynamic program for an economy with one consumption good sufficient conditions are given for the existence of a unique interior stationary distribution of consumption and wealth for a two person exchange economy sufficient conditions are given for the global asymptotic stability of the unique interior stationary point

demographic dynamics in poor countries labour market conditions and gender inequalities abstract this article analyses a stackelberg differential game in which households labour supply and fertility decisions are taken assuming husbands as leaders and wives as followers the model solution yields the optimal number of children and labour supply of male and female in equilibrium male and female labour supply increases with wage and decreases with children costs and time preference and the optimal number of children increases with male wage and decreases with cost of children husband s time preference and female s wage and time preference we test the model using ghana living standard survey round 4 and find that women are more sensitive to changes in the labour market conditions than males and better labour market opportunities for women may lead to a strong reduction in fertility

optimal capital income taxation with incomplete markets borrowing constraints and constant discounting for a wide class of infinitely lived agent models chamley has shown that the optimal capital income tax rate is zero in the long run lucas has argued that for the u s economy there is a significant welfare gain from switching to this policy this paper shows that for the bewley class of models with incomplete insurance markets and borrowing constraints the optimal tax rate on capital income is positive even in the long run therefore cutting the capital income tax to zero may well lead to welfare losses

the one sector growth model with idiosyncratic shocks steady states and dynamics abstract this paper investigates the one sector growth model where agents receive idiosyncratic labor endowment shocks and face a borrowing constraint it is shown that any steady state capital stock lies strictly above the steady state in the model without idiosyncratic shocks in addition the capital stock increases monotonically when it is sufficiently far below a steady state however near a steady state there can be non monotonic economic dynamics

revealing preferences for leisure time from stated preference data when consumer choice is constrained by time as well as money willingness to pay can be defined with respect to either numeraire the two measures can be related formally within a utility consistent model of choice subject to two constraints furthermore when information is collected on both the respondent s marginal value of time can be identified a system of willingness to pay time and money and the marginal value of leisure time is estimated jointly in an application to california whalewatching and whale stock enhancement the empirical approach can be applied with only minor additions to survey techniques for nonmarket valuation

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

estimating the cost of leisure time for recreation demand models abstract in this paper we propose a method of determining the opportunity cost of leisure time with an empirical recreation demand application typically the opportunity cost of leisure time is assumed to be some fraction of the wage rate this practice has limitations first it assumes that individuals can trade time for money at their wage second it offers no guidance about how to value the time of an individual who is not in the labor force this paper proposes a method of determining this cost that does not suffer from these drawbacks an empirical example is provided which demonstrates the proposed approach and contrasts it with commonly applied approaches

how important is anticipation of divorce in married women s labor supply decisions an intercohort comparison using nls data abstract i compare two birth cohorts of married women and find that divorce risk plays a significantly smaller role in the recent cohort s labor supply decision this suggests that any decline in america s divorce rates will not substantially reduce married women s labor supply

a characterization of ramsey equilibrium abstract consider a perfect foresight equilibrium model with a single capital good a borrowing constraint and many infinitely lived households with fixed but different discount factors the steady state capital stock is held by the most patient household quart j econ 95 1980 375 382 econ j 38 1928 543 559 an example shows the total capital can exhibit an equilibrium cycle in contrast to the stability property of the one household case in the example only the most patient household saves and his income deceases in capital we give a condition implying income is increasing in capital and use it to show any equilibrium converges to the steady state

the relationship between hours of work and labor force participation in four models of labor supply behavior this article analyzes the relationship between hours of work and labor force participation lfp in heckman s model cogan s fixed cost model moffitt s minimum hours constraint model and a generalized version of heckman s model first the parameter restrictions between the lfp and reduced form hours of work equations are compared the models are then estimated and the results support the weakening of the link between the lfp and hours of work decisions one implication of the analysis is that heckman s model overstates the standard labor supply elasticities because it confounds the direct effect on labor supply with the participation effect

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

redistributive taxation in a simple perfect foresight model abstract we investigate the redistributive potential of capital taxation in an intertemporal maximizing model of capital formation first even unanticipated redistributive capital taxation is severely limited in its effectiveness since it depresses wages second under any convergent redistributive tax policy which maximizes a paretian social objective the capital income tax will converge to zero independent of the factor supply elasticities these results are independent of workers holdings of capital

the demand for leisure time in the presence of constrained work hours w douglass shaw this article presents a labor supply model designed to address situations of overemployment or underemployment in the labor market previous labor supply models have taken the possibility of work hour constraints into consideration but typically assumed that the existence of fixed work hours only influenced the decision of labor force participation this ignores situations in which individuals choose to be employed at fixed hour jobs even though these jobs do not offer the desired work hours jel j22 i introduction early attempts to incorporate time into consumer theory such as those by becker 1965 and by deserpa 1971 and to explain behavior in labor markets such as heckman s 1974 pioneering study relied on the assumption that individuals are able to freely adjust the hours they work the ability of an individual to achieve equilibrium in these models depends on flexible work hours for many individuals however hours of work are likely to be constrained individuals wishing to increase or decrease their work time may face a decision of either accepting the fixed hour schedule or exiting the labor force more refined models of labor force participation put forth by moffitt 1982 tummers and woittiez 1990 and zabel 1993 recognized this by incorporating a fixed hour constraint directly into the labor force participation decision generally these models assume that individuals decide whether or not to accept employment by comparing offered hours with desired hours if desired hours exceed offered hours then the individual enters the labor force models with a fixed hour constraint represent an improvement but they ignore the possibility that a large proportion of the labor force is likely to be either underemployed or overemployed due to the ubiquity of fixed hour employment the presence of these types of jobs is well documented in the literature schor 1991 lists several reasons including lack of lower skilled jobs costly fringe benefits and increased business competition why underemployment and overemployment is prevalent in the u s workplace prior studies by mossin and bronfenbrenner 1967 and by altonji and paxson 1988 document underemployment in the workplace in a study of the u s work force ham 1982 found that unemployed and underemployed workers ranged from 19 2 in 1973 to 28 2 in 1970 1 on the overemployment side tarling 1987 claims that recent evidence indicates that many employees would be prepared to forgo some of their earnings in order to reduce their hours of work p 85 bockstael et al 1987 make a simi lar observation noting that in their sample individuals with fixed working hours appear to value time much more highly than the wage rate and would be willing to trade work for leisure p 301 hahnel 1998 concluded that results from a 1994 survey suggest that u s workers have a slight preference for pay cuts in order to reduce their work hours about 50 of the respondents claimed they would accept a 10 reduction in pay in order to work a four day week well over half of the respondents in the survey claimed that it was either fairly difficult or almost impossible to reduce their work hours and over 60 reported that reducing their work hours would have a negative impact on their careers although the existence of underemployment and overemployment is well documented explicitly accounting for it in labor supply models remains largely unexplored in the literature in this paper the labor supply model originally analyzed by heckman 1974 is extended to recognize and incorporate fixed hour situations heckman s model which has been described as the most prevalent in the literature by zabel 1993 is derived by comparing reservation and market wages in its original form it posited a strong link between the labor force participation decision and the labor supply decision

identifying the elasticity of taxable income we use matched panels from the current population survey along with a grouping instrumental variables estimator to provide new estimates of the elasticity of taxable income our identification strategy exploits the fact that federal and state tax reforms over the past three decades have differentially affected cohorts across states and over time we find that the elasticity is in the range of 0 4 0 55 the implication of our new estimates for tax policy is that the revenue maximising tax rate is nearly 30 percentage points lower than that obtained when we use the typical identification strategy in the literature

capital income taxation wealth distribution and borrowing constraints the theorem of zero taxation of capital income is reexamined and is shown to hinge critically on the assumptions of a long horizon and perfect markets for the inter temporal allocation of resources the theorem does not hold when borrowing constraints prevent individuals from insuring against idiosyncratic shocks and have a precautionary motive for savings structural assumptions are made such that with no taxation aggregate savings are socially excessive in the long run i e the rate of return is smaller than the discount rate sufficient conditions for a pareto efficient taxation or subsidization of capital in the long run depend on the correlation between individuals consumption and savings a subsidy may be efficient when individuals incomes follow a predictable pattern of life cycles with no negative bequest 2001 elsevier science b v all rights reserved

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

stationary ramsey equilibria under uncertainty abstract deterministic dynamic equilibrium models with borrowing constraints and heterogeneous agents exhibit stationary solutions where the most patient household owns the economy s capital stock an example shows that this result does not carry over to stationary stochastic environments we prove under some conditions the existence of a stationary rational expectations equilibrium in two related setups the first is the existence of a stationary nash equilibrium where each agent s payoff depends on his capital process and the capital processes of the remaining agents the second existence theorem applies to a stationary competitive equilibrium model journal of economic literatureclassification numbers e13 e21 d80

introduction to a general equilibrium approach to economic growth abstract endogenous growth theory has had some success in explaining the observed data related to the process of economic growth however the results of the models in this literature are typically very sensitive to their micro economic structure it is therefore important to understand how the growth process behaves under more general specifications of such features as the number of commodities the number and preferences of consumers the factors of production and the financial and information structures in other words valuable insights can be gained by integrating growth theory into the framework of general equilibrium theory the summary of the papers in this volume focuses on seven issues that are crucial to this integration and highlights the contributions of the papers to the resolution of these issues journal of economic literature classification numbers c61 d50 d90 f43 o30 o41

time preference and the distributions of wealth and income this paper presents a dynamic competitive equilibrium model in which heterogeneity in time preferences alone can generate the observed patterns of wealth and income inequality in the united states this model generalizes the standard deterministic neoclassical growth model by introducing i a direct preference for wealth by the consumers and ii human capital formation the rst feature prevents the wealth distribution from collapsing into a degenerate distribution the second feature generates a strong positive correlation between earnings and wealth across agents a calibrated version of this model is able to replicate the wealth and income distributions of the united states

short term contracts and long term agency relationships abstract long term contracts are valuable only if optimal contracting requires commitment to a plan today that would not otherwise be adopted tomorrow we show that commitments are unnecessary and hence short term contracts are sufficient if 1 all public information can be used in contracting 2 the agent can acess a bank on equal terms with the principal 3 recontracting takes place with common knowledge about technology and preferences and 4 the frontier of expected utility payoffs generated by the set of incentive compatible contracts is downward sloping at all times

positive long run capital taxation chamley judd revisited according to the chamley judd result capital should not be taxed in the long run in this paper we overturn this conclusion showing that it does not follow from the very models used to derive it for the main model in judd 1985 we prove that the long run tax on capital is positive and significant whenever the intertemporal elasticity of substitution is below one for higher elasticities the tax converges to zero but may do so at a slow rate after centuries of high tax rates the main model in chamley 1986 imposes an upper bound on capital taxes we provide conditions under which these constraints bind forever implying positive long run taxes when this is not the case the long run tax may be zero however if preferences are recursive and discounting is locally nonconstant e g not additively separable over time a zero long run capital tax limit must be accompanied by zero private wealth zero tax base or by zero labor taxes first best finally we explain why the equivalence of a positive capital tax with ever increasing consumption taxes does not provide a firm rationale against capital taxation

on ramsey s conjecture efficient allocations in the neoclassical growth model with private information abstract in his seminal paper of 1928 ramsey conjectured that if agents discounted the future differently in the long run all agents except the most patient would live at the subsistence level the validity of this conjecture was investigated in different environments in particular it has been confirmed in the neoclassical growth model with dynamically complete markets this paper studies this conjecture in a version of this model that includes private information and heterogeneous agents a version of bayesian implementation is introduced and a recursive formulation of the original allocation problem is established efficient allocations are renegotiation proof and the expected utility of any agent cannot go to zero with positive probability if the economy does not collapse if the economy collapses all agents will get zero consumption forever thus including any degree of private information in the neoclassical growth model will deny ramsey s conjecture if efficient allocations are considered

the sensitivity of an empirical model of married women s hours of work to economic and statistical assumptions this study undertakes a systematic analysis of several theoretic and statistical assumption s used in many empirical models of female labor supply using a singl e data set psid 1975 labor supply data the author is able to replic ate most of the range of estimated income and substitution effects fo und in previous studies in this field he undertakes extensive specif ication tests and finds that most of this range should be rejected du e to statistical and model misspecifications the two most important assumptions appear to be the tobit assumption used to control for sel f selection into the labor force and exogeneity assumptions on the wi fe s wage rate and her labor market experience copyright 1987 by the econometric society

communication commitment and growth abstract we study the effect on the growth of an economy of alternative financing opportunities in a stochastic growth model with incentive constraints efficient accumulation mechanisms are designed and computed for economies that differ in their incentive structure we show that when borrowing is subject to information constraints there is a computable efficient transfer mechanism that does not affect capital accumulation and investment patterns even though consumption patterns and the distribution of wealth are affected in contrast enforcement constraints can severely reduce the outside financing opportunities and affect investment patters and economic growth we adapt numerical algorithms for obtaining numerical solutions of these models

on the long run implications of repeated moral hazard abstract this paper analyzes the effects of moral hazard on long run consumption or utility given exponential utility it is shown that the utility of those with unobservable endowments becomes arbitrarily negative as long as any positive fraction of otherwise identical agents have observable endowments next it is shown that assuming a finite number of agents results in essentially the same outcomes as with a continuum of agents finally it is shown that the key characteristic determining whether the utility of almost all agents becomes arbitrarily low is whether lim c u c is bounded away from zero journal of economic literature classification numbers d30 d31 d80 d82

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

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

investment and bilateral insurance abstract private information may limit insurance possibilities when two agents get together to pool idiosyncratic risk however if there is capital accumulation bilateral insurance possibilities may improve because misreporting distorts investment we show that if one of the pareto weights is sufficiently large that agent does not have incentives to misreport this implies that under some conditions the full information allocation is incentive compatible when agents have equal pareto weights in the long run either one of the agents goes to immiseration or both agents lifetime utilities are approximately equal the second case is only possible with capital accumulation

optimal taxation of capital income in general equilibrium with infinite lives this paper analyzes the optimal tax on capital income in general equilibrium models of the second best agents have infinite lives and utility functions which are extensions from the koopmans form the population is heterogeneous the important property of the models is the equality between the social and the private discount rates in the long run i find that the optimal tax rate is zero in the long run for a special case of additively separable utility functions i then determine the tax rates along the dynamic path and conditions that are sufficient for the local stability of the steady state

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

international lending with moral hazard and risk of repudiation in this paper i examine the constrained optimal pattern of capital flows between a lender and a borrower in an environment in which there are two impediments to forming contracts the first impediment to contracting arises from the assumption that lenders cannot observe whether borrowers invest or consume borrowed funds this assumption leads to a moral hazard problem in investment the second impediment arises from the assumption that the borrower as a sovereign nation may choose to repudiate his debts the optimal contract is shown to specify that the borrowing country experience a capital outflow when the worst realizations of national output occur this seemingly perverse capital outflow forms a necessary part of the optimal solution to the moral hazard problem in investment

an exogeneity test for a simultaneous equation tobit model with an application to labor supply a test of weak exogeneity in the simultaneous equation tobit model is proposed and illustrated using a female labour supply model estimated using cross section data the test statistic can be simply output from any standard tobit maximum likelihood package and is asymptotically efficient the procedure provides consistent estimators for the simultaneous tobit model whose asymptotic covariance matrix is a simple extension of the usual tobit formula we also provide the lagrange multiplier test of weak exogeneity this abstract was borrowed from another version of this item