learning your earning are labor income shocks really very persistent in this paper we examine the risk situation facing individuals in the labor market the current consensus in the literature is that the labor income process has a large random walk component we argue two points first the estimates of persistence from income data appear to be upward biased due to the omission of heterogeneity in income pro les across the population that would be implied for example by a human capital model with heterogeneity when we allow for dierences in pro les the estimated persistence falls from 0 99 to about 0 8 moreover the main evidence against pro le heterogeneity in the existing literature that the autocorrelations of income changes are small and typically negative is also replicated by the pro le heterogeneity model we estimate casting doubt on the previous interpretation of this evidence second we embed this process in a life cycle model to examine how it alters individuals consumption saving decision we assume that as seems plausible individuals do not know their pro les exactly at the beginning of life but learn in a bayesian way with successive income observations we nd that learning is very slow and aects consumption decision throughout the life cycle the model generates substantial rise in consumption inequality over the life cycle which matches empirical observations deaton and paxson 1994 moreover the shape of the age inequality pro le is non concave as in the data but unlike in a model with very persistent shocks finally the consumption pro les of college graduates are steeper than those of high school graduates in the model consistent with the data because they face a wider dispersion of and hence uncertainty about income growth rates overall this evidence indicates that income shocks may be signi cantly less persistent than what is currently assumed

intertemporal labor supply and human capital accumulation we solve and estimate a dynamic model that allows agents to optimally choose their labor hours and consumption and that allows for both human capital accumulation and savings estimation results and simulation exercises indicate that the intertemporal elasticity of substitution is much higher than the conventional estimates and the downward bias comes from the omission of the human capital accumulation effect the human capital accumulation effect renders the life cycle path of the shadow wage relatively flat even though wages increase with age hence a rather flat life cycle labor supply path can be reconciled with a high intertemporal elasticity of substitution

financial crises unconventional monetary policy exit strategies and agents expectations a central bank may purchase assets during a financial crisis and then exit from those purchases agents have rational expectations about financial crises as rare events the probability the central bank purchases assets and the exit strategy selling off assets quickly produces a double dip recession while slowly unwinding generates a smooth recovery expectations about the exit strategy influence the initial effectiveness of purchases increasing the probability of purchases during crises distorts the pre crisis economy and depends upon the exit strategy the welfare benefits of unconventional policy may differ ex ante versus ex post as can the preferred exit strategy

income dynamics and life cycle inequality mechanisms and controversies this study focuses on the transmission of inequality over the working life a model of constrained intertemporal choice is used to provide structure to the distributional dynamics of wages earnings income and consumption the mechanisms used to insure labour market shocks are examined in a partial insurance setting where the manner and scope for insurance depends on the access to credit the information available to consumers and the durability of income shocks drawing on recent research family labour supply the credit market and the tax system are all shown to play a key role these mechanisms vary in importance across different points of the life cycle and the business cycle 2014 the author s the economic journal published by john wiley sons ltd on behalf of royal economic society

wealth distribution in life cycle economies abstract this paper compares the age wealth distribution produced in life cycle economies to the corresponding distribution in the us economy the idea is to calibrate the model economies to match features of the us earnings distribution and then examine the wealth distribution implications of the model economies the findings are that the calibrated model economies with earnings and lifetime uncertainty can replicate measures of both aggregate wealth and transfer wealth in the us furthermore the model economies produce the us wealth gini and a significant fraction of the wealth inequality within age groups however the model economies produce less than half the fraction of wealth held by the top 1 percent of us households

2018 klein lecture individual and aggregate labor supply in heterogeneous agent economies with intensive and extensive margins we study business cycle fluctuations in heterogeneous agent general equilibrium models featuring intensive and extensive margins of labor supply a nonlinear mapping from time devoted to work to labor services generates operative extensive and intensive margins our model captures the salient features of the empirical distribution of hours worked including how individuals transit within this distribution we study how various specifications influence labor supply responses to aggregate technology shocks and find that abstracting from intensive margin adjustment can have large effects on the volatility of aggregate hours even if fluctuations along the intensive margin are small

a new method of estimating risk aversion i show existing evidence on labor supply behavior places an upper bound on risk aversion in the expected utility model i derive a formula for the coefficient of relative risk aversion in terms of the ratio of the income elasticity of labor supply to wage elasticity and degree of complementarity between consumption and labor i bound the degree of complementarity using data on consumption choices when labor supply varies across states using labor supply elasticity estimates i find a mean estimate of 1 then show generating 2 requires that wage increases cause sharper labor supply reductions jel d81 j22

cyclical dynamics in idiosyncratic labor market risk is individual labor income more risky in recessions this is a difficult question to answer because existing panel data sets are so short to address this problem we develop a generalized method of moments estimator that conditions on the macroeconomic history that each member of the panel has experienced variation in the cross sectional variance between households with differing macroeconomic histories allows us to incorporate business cycle information dating back to 1930 even though our data do not begin until 1968 we implement this estimator using household level labor earnings data from the panel study of income dynamics we estimate that idiosyncratic risk is i highly persistent with an annual autocorrelation coefficient of 0 95 and ii strongly countercyclical with a conditional standard deviation that increases by 75 percent from 0 12 to 0 21 as the macroeconomy moves from peak to trough

has consumption inequality mirrored income inequality we revisit to what extent the increase in income inequality since 1980 was mirrored by consumption inequality we do so by constructing an alternative measure of consumption expenditure using a demand system to correct for systematic measurement error in the consumer expenditure survey our estimation exploits the relative expenditure of high and low income households on luxuries versus necessities this double differencing corrects for measurement error that can vary over time by good and income we find consumption inequality tracked income inequality much more closely than estimated by direct responses on expenditures jel d31 d63 e21

taxation and household labor supply we evaluate reforms to the u s tax system in a life cycle setup with heterogeneous married and single households and with an operative extensive margin in labor supply we restrict our model with observations on gender and skill premia labor force participation of married females across skill groups children and the structure of marital sorting we concentrate on two revenue neutral tax reforms a proportional income tax and a reform in which married individuals flle taxes separately separate flling our flndings indicate that tax reforms are accompanied by large increases in labor supply that difier across demographic groups with the bulk of the increase coming from married females under a proportional income tax reform married females account for more than 50 of the changes in hours across steady states while under separate flling reform married females account for all the change in hours

sources of lifetime inequality is lifetime inequality mainly due to differences across people established early in life or to differences in luck experienced over the working lifetime we answer this question within a model that features idiosyncratic shocks to human capital estimated directly from data as well as heterogeneity in ability to learn initial human capital and initial wealth we find that as of age 23 differences in initial conditions account for more of the variation in lifetime earnings lifetime wealth and lifetime utility than do differences in shocks received over the working lifetime jel d31 d91 j24 j31 to what degree is lifetime inequality due to differences across people established early in life as opposed to differences in luck experienced over the working lifetime among the individual differences established early in life which ones are the most important a convincing answer to these questions is of fundamental importance first and most simply an answer serves to contrast the potential importance of the myriad policies directed at modifying or at providing insurance for initial conditions e g public education against those directed at shocks over the working lifetime e g unemployment insurance second a discussion of lifetime inequality cannot go too far before discussing which specific type of initial condition is the most critical for determining how one fares in life third a useful framework for answering these questions should also be central in the analysis of a wide range of policies considered in macroeconomics public finance and labor economics we view lifetime inequality through the lens of a risky human capital model agents differ in terms of three initial conditions initial human capital learning ability and financial wealth initial human capital can be viewed as controlling the intercept of an agent s mean earnings profile whereas learning ability acts to rotate

transitional dynamics and the distribution of wealth in a neoclassical growth model abstract the evolution of the personal distribution of wealth in a standard neoclassical growth model is studied if the economy is growing toward the steady state and preferences are such that marginal utility from consumption is infinite finite at some all positive non negative consumption level s then the average saving propensity of agents is positively negatively related to their wealth if the economy is decaying toward the steady state these relationships are reversed if wealth and average saving propensity are positively negatively related the distribution of current period wealth lorenz dominates is lorenz dominated by next period s distribution of wealth

efficient allocations in dynamic private information economies with persistent shocks a first order approach this article studies efficient allocations in a dynamic private information economy with a continuum of idiosyncratic shocks that are persistent i develop a first order approach for this environment and show that the problem has a simple recursive structure that relies on only a small number of state variables making the problem tractable i find sufficient conditions that guarantee that the first order approach is valid to illustrate the first order approach i numerically compute the efficient allocations in a mirrleesean economy with productivity shocks that follow a random walk and verify the validity of the first order approach i show that persistent shocks create a new trade off where the social planner decreases the informational rent of the agent today at the cost of providing higher insurance in the future copyright 2013 oxford university press

towards a micro founded theory of aggregate labour supply we build a heterogeneous agents life cycle model that captures a large number of salient features of individual male labour supply over the life cycle by education both along the intensive and extensive margins the model provides an aggregation theory of individual labour supply firmly grounded on individual level micro evidence and is used to study the aggregate labour supply responses to changes in the economic environment we find that the aggregate labour supply elasticity to a transitory wage shock is 1 75 with the extensive margin accounting for 62 of the response furthermore we find that the aggregate labour supply elasticity to a permanent compensated wage change is 0 44

africa energy future alternative scenarios and their implications for sustainable development strategies abstract the long term forecasting of energy supply and demand is of prime importance in africa due to the steady increase in energy requirements the non availability of sufficient resources the high dependence on fossil fuels to meet these requirements and the global concerns over the energy induced environmental issues this paper is concerned with modelling possible future paths for africa s energy future and the related emissions future energy demand is forecasted based on socio economic variables such as gross domestic product income per capita population and urbanisation the long range energy alternative planning system leap modelling framework is employed to analyse and project energy demand and the related emissions under alternative strategies for the period of 2010 2040 results of scenarios including business as usual bau policies moderate energy access and accelerate energy access policies renewable energies promotion and energy efficiency policies and their environmental implications are provided the study provides some policy insights and identifies synergies and trade offs relating to the potential for energy policies to promote universal energy access enable a transition to renewable energy and mitigate climate change for a sustainable development

two views of inequality over the life cycle data on the life cycle profiles of inequality in wages earnings hours worked and consumption contain precious information for answering questions about the ability of households to insure labor market risk and about the sources of this risk this paper demonstrates that the choice of whether to control for cohort effects or for time effects has a drastic impact on the estimated age profiles for inequality and thus on the answers to those questions it also shows that time effects are required to account of the observed trends in inequality in 30 years of u s data whereas there is no evidence that cohort effects have been important jel c13 d31 d91 j22 j31

consumption inequality and family labor supply we examine the link between wage and consumption inequality using a life cycle model incorporating consumption and family labor supply decisions we derive analytical expressions for the dynamics of consumption hours and earnings of two earners in the presence of correlated wage shocks nonseparability progressive taxation and asset accumulation the model is estimated using panel data for hours earnings assets and consumption we focus on family labor supply as an insurance mechanism and find strong evidence of smoothing of permanent wage shocks once family labor supply assets and taxes are properly accounted for there is little evidence of additional insurance jel d12 d14 d91 j22 j31

evidence on the validity of cross sectional and longitudinal labor market data this article investigates error properties of survey reports of labor market variables we use the panel study of income dynamics psid validation study a two wave panel survey of workers employed by a large firm that shared its detailed payroll records individuals reports of annual earnings are fairly accurate errors are negatively related to true earnings reducing bias due to measurement error when earnings are used as an independent variable biases are moderately larger for changes in earnings earnings per hour are less reliably reported than annual earnings biases in estimating earnings functions are relatively small but those in labor supply functions may be important

consumer bankruptcy a fresh start consumer bankruptcy provides partial insurance against bad luck but by driving up interest rates makes life cycle smoothing more difficult we argue that to assess this trade off one needs a quantitative model of consumer bankruptcy with three key features life cycle component idiosyncratic earnings uncertainty and expense uncertainty exogenous negative shocks to household balance sheets we find that transitory and persistent earnings shocks have very different implications for evaluating bankruptcy rules more persistent shocks make the bankruptcy option more desirable larger transitory shocks have the opposite effect our findings suggest the current us bankruptcy system may be desirable for reasonable parameter values jel d14 d91 k35

trends in the transitory variance of earnings in the united states we decompose the rise in cross sectional variance of male annual earnings in the united states from 1969 to 1996 into permanent and transitory components we find that the variance of permanent earnings began rising in the the late 1970s and has continued to rise in the 1980s the variance of transitory earnings also rose in the 1980s but declined in the 1990s there are lags in the earnings process which require a structural model to pinpoint the exact calendar times at which the changes in trends occurred

education policy and intergenerational transfers in equilibrium this paper compares partial and general equilibrium effects of alternative financial aid policies intended to promote college participation we build an overlapping generations life cycle heterogeneous agent incomplete markets model with education labor supply and consumption saving decisions altruistic parents make inter vivos transfers to their children labor supply during college government grants and loans as well as private loans complement parental transfers as sources of funding for college education we find that the current financial aid system in the u s improves welfare and removing it would reduce gdp by two percentage points in the long run any further relaxation of government sponsored loan limits would have no salient effects the short run partial equilibrium effects of expanding tuition grants especially their need based component are sizeable however long run general equilibrium effects are 3 4 times smaller every additional dollar of government grants crowds out 20 30 cents of parental transfers

earnings and consumption dynamics a nonlinear panel data framework we develop a new quantile based panel data framework to study the nature of income persistence and the transmission of income shocks to consumption log earnings are the sum of a general markovian persistent component and a transitory innovation the persistence of past shocks to earnings is allowed to vary according to the size and sign of the current shock consumption is modeled as an age dependent nonlinear function of assets unobservable tastes and the two earnings components we establish the nonparametric identification of the nonlinear earnings process and of the consumption policy rule exploiting the enhanced consumption and asset data in recent waves of the panel study of income dynamics we find that the earnings process features nonlinear persistence and conditional skewness we confirm these results using population register data from norway we then show that the impact of earnings shocks varies substantially across earnings histories and that this nonlinearity drives heterogeneous consumption responses the framework provides new empirical measures of partial insurance in which the transmission of income shocks to consumption varies systematically with assets the level of the shock and the history of past shocks

accounting for the u s earnings and wealth inequality we show that a theory of earnings and wealth inequality based on the optimal choices of ex ante identical households that face uninsured idiosyncratic shocks to their endowments of efficiency labor units accounts for the u s earnings and wealth inequality almost exactly

understanding consumption smoothing evidence from the u s consumer expenditure data consumption models with endogenous debt constraints differ from standard incomplete markets models in their predictions about an individual household s ability to smooth consumption across time and states of the world in this paper we develop these differences both theoretically and quantitatively we then use data from the us consumer expenditure survey ce to assess along which dimensions the predictions of these models are consistent with the empirical evidence we find that both type models fail to fully account for the data and argue that a model that combines aspects of both might be more succesfull

labor supply in the past present and future a balanced growth perspective the absence of a trend in hours worked in the postwar united states is an exception across countries and historically hours fall steadily by a little below 0 5 per year are steadily falling hou

relative wage movements and the distribution of consumption we analyze how relative wage movements among birth cohorts and education groups affected the distribution of household consumption and economic welfare our empirical work draws on the best available cross sectional data sets to construct synthetic panel data on u s consumption labor supply and wages during the 1980s we find that low frequency movements in the cohort education structure of pretax hourly wages among men drove large changes in the distribution of household consumption the results constitute a spectacular failure of between group consumption insurance a failure not explained by existing theories of informationally constrained optimal consumption behavior a welfare analysis indicates that the cost of between group consumption variability is larger than the cost of aggregate consumption variability by two orders of magnitude

testing efficient risk sharing with heterogeneous risk preferences previous papers have tested e cient risk sharing under the assumption of identical risk preferences in this paper we show that if in the data households have heterogeneous risk preferences the tests proposed in the past reject e ciency even if households share risk e ciently to address this issue we propose a method that enables one to test e ciency even when households have difierent preferences for risk the method is composed of three tests the flrst one can be used to determine whether in the data under investigation households have homogeneous risk preferences the second and third test can be used to evaluate e cient risk sharing when the hypothesis of homogeneous risk preferences is rejected we use this method to test e cient risk sharing in rural india using the flrst test we strongly reject the hypothesis of identical risk preferences we then test e ciency with and without the assumption of preference homogeneity in the flrst case we reject e cient risk sharing at the village and caste level in the second case we still reject e ciency at the village level but we cannot reject this hypothesis at the caste level this flnding suggests that the relevant risk sharing unit in rural india is the caste and not the village

saving and liquidity constraints this paper is concerned with the theory of saving when consumers are not permitted to borrow and with the ability of such a theory to account for some of the stylized facts of saving behavior the models presented in the paper seem to account for important aspects of reality that are not explained by traditional life cycle models copyright 1991 by the econometric society

labor supply and taxes a survey i survey the male and female labor supply literatures focusing on implications for effects of wages and taxes for males i describe and contrast results from three basic types of model static models especially those that account for nonlinear taxes life cycle models with savings and life cycle models with both savings and human capital for women more important distinctions are whether models include fixed costs of work and whether they treat demographics like fertility and marriage and human capital as exogenous or endogenous the literature is characterized by considerable controversy over the responsiveness of labor supply to changes in wages and taxes at least for males it is fair to say that most economists believe labor supply elasticities are small but a sizeable minority of studies that i examine obtain large values hence there is no clear consensus on this point in fact a simple average of hicks elasticities across all the studies i examine is 0 30 several simulation studies have shown that such a value is large enough to generate large welfare costs of income taxation for males i conclude that two factors drive many of the differences in results across studies one factor is use of direct vs ratio wage measures with studies that use the former tending to find larger elasticties another factor is the failure of most studies to account for human capital returns to work experience i argue that this may lead to downward bias in elasticity estimates in a model that includes human capital i show how even modest elasticities as conventionally measured can be consistent with large welfare costs of taxation

the persistence of financial distress using recently available proprietary panel data we show that while many 35 us consumers experience financial distress at some point in the life cycle most of the events of financial distress are primarily concentrated in a much smaller proportion of consumers in persistent trouble roughly 10 of consumers are distressed for more than a quarter of the life cycle and less than 10 of borrowers account for half of all distress events these facts can be largely accounted for in a straightforward extension of a workhorse model of defaultable debt that accommodates a simple form of heterogeneity in time preference but not otherwise

partial insurance and investments in children this article studies the impact of permanent and transitory shocks to income on parental investments in children we use panel data on family income and an index of investments in children from the children of the national longitudinal survey of youth we find that there is partial insurance of parental investments against permanent income shocks but the magnitude of the estimated responses is small we cannot reject the hypothesis of full insurance against temporary shocks another interpretation of our findings is that insurance possibilities are limited but the fact that skill is a non separable function of parental investments over time results in small reactions of these investments to income shocks especially at later ages

earnings instability and tenure we study the effect of tenure on earnings instability in italy using two alternative estimation strategies first we use a descriptive measure of earnings instability and fixed effects regressions second we develop a formal model of earnings dynamics distinguishing permanent from transitory earnings and exploit variation of tenure and instability over time and across birth cohorts in estimation we use the two approaches also to evaluate earnings instability associated with temporary contracts short tenure contracts our results indicate that each year of tenure on the job reduces earnings instability on average by 11 workers on a temporary contract have an earnings instability up to 50 higher than workers on a permanent contract

rising inequality changes in the distribution of income and consumption in the 1980s this paper examines changes in the distribution of income and consumption in the united states during the 1980s using data from the current population survey income and consumer expenditure survey consumption we reach three primary conclusions first changes in the distribution of consumption parallel changes in the distribution of income the lowest quintile of the consumption distribution received 0 9 percentage points less of total consumption in 1988 than in 1980 the corresponding decline for income was 0 6 percentage points second broad conclusions concerning recent changes in the consumption distribution are not very sensitive to the exact choice of a measure of family needs under a wide variety of alternative household equivalence scales there is a widening in the consumption distribution in the 1980s third the usc of consumption measures of well being in place of measures based on current money income docs change conclusions concerning the extent of poverty in the united stales using the official federal poverty thresholds we find that the overall consumption poverty rate was three percentage points below the income poverty rate in 1988 comparisons of the poverty rates of the elderly and the non elderly are substantially affected by the choice of poverty measure the consumption poverty rare for the elderly was only 60 percent of the rate for adults and one third of the rate for children in 1988 this abstract was borrowed from another version of this item

the value of registry data for consumption analysis an application to health shocks abstract this paper measures consumption expenditures using registry data on income and asset holdings in sweden we show how a registry based measure complements traditional survey measures of consumption and can alleviate some critical limitations we describe the construction of our measure which builds on prior work and exploits the identity coming from the household budget constraint between consumption expenditures and income net of savings we demonstrate the value of the registry based measure to study consumption responses to shocks also relative to surveyed consumption in our application to health shocks we find that swedish household experience permanent earning drops but generous social transfers provide substantial consumption smoothing we document important heterogeneity in consumption responses and the limited role for private means

how should tax progressivity respond to rising income inequality we address this question in a heterogeneous agent incomplete markets model featuring exogenous idiosyncratic risk endogenous skill investment and flexible labor supply the tax and transfer schedule is restricted to be log linear in income a good description of the us system rising inequality is modeled as a combination of skill biased technical change and growth in residual wage dispersion when facing shifts in the income distribution like those observed in the us a utilitarian planner chooses higher progressivity in response to larger residual inequality but lower progressivity in response to widening skill price dispersion reflecting technical change overall optimal progressivity is approximately unchanged between 1980 and 2016 we document that the progressivity of the actual us tax and transfer system has similarly changed little since 1980 in line with the model prescription

insurance and opportunities a welfare analysis of labor market risk abstract using a model with constant relative risk aversion preferences endogenous labor supply and partial insurance against idiosyncratic wage risk this paper provides an analytical characterization of three welfare effects a the welfare effect of a rise in wage dispersion b the welfare gain from completing markets and c the welfare effect from eliminating risk the analysis reveals an important trade off for these welfare calculations on the one hand higher wage uncertainty increases the cost associated with missing insurance markets on the other hand greater wage dispersion presents opportunities to raise aggregate productivity by concentrating market work among more productive workers welfare effects can be expressed in terms of the underlying parameters defining preferences and wage risk or alternatively in terms of changes in observable second moments of the joint distribution over individual wages consumption and hours

inferring labor income risk and partial insurance from economic choices this paper uses the information contained in the joint dynamics of individuals labor earnings and consumption choice decisions to quantify both the amount of income risk that individuals face and the extent to which they have access to informal insurance against this risk we accomplish this task by using indirect inference to estimate a structural consumption savings model in which individuals both learn about the nature of their income process and partly insure shocks via informal mechanisms in this framework we estimate i the degree of partial insurance ii the extent of systematic differences in income growth rates iii the precision with which individuals know their own income growth rates when they begin their working lives iv the persistence of typical labor income shocks v the tightness of borrowing constraints and vi the amount of measurement error in the data in implementing indirect inference we find that an auxiliary model that approximates the true structural equations of the model which are not estimable works very well with negligible small sample bias the main substantive findings are that income shocks are moderately persistent systematic differences in income growth rates are large individuals have substantial amounts of information about their income growth rates and about one half of income shocks are smoothed via partial insurance putting these findings together the amount of uninsurable lifetime income risk that individuals perceive is substantially smaller than what is typically assumed in calibrated macroeconomic models with incomplete markets

risk sharing between and within families this paper uses the panel study of income dynamics to test whether risk sharing is complete between or within american families the tests accommodate a wide variety in the configuration and availability of family data the test results reject inter as well as intra family full risk sharing even assuming that leisure is endogenous or that leisure and consumption are nonseparable

why is consumption so smooth for thirty years it has been accepted that consumption is smooth because permanent income is smoother than measured income this paper considers the evidence for the contrary position that permanent income is in fact less smooth than measured income so that the smoothness of consumption cannot be straightforwardly explained by permanent income theory the paper argues that in postwar u s quarterly data consumption is smooth because it responds with a lag to changes in income

intergenerational mobility new evidence from consumption data the intergenerational persistence of consumption describes the extent to which children inherit the living standards of their parents evidence on this parameter is scarce due to limited data on the joint consumption of parents and children this paper identifies parents who participated in the danish expenditure survey links them to their children through population wide danish registries and estimates the intergenerational elasticity of consumption in denmark the results suggest that consistent with intergenerational consumption smoothing the persistence of consumption across generations is higher than the persistence of earnings and income

human capital risk and economic growth this paper develops a tractable incomplete markets model of economic growth in which households invest in risk free physical capital and risky human capital the paper shows that a reduction in uninsurable idiosyncratic labor income risk decreases physical capital investment but increases human capital investment growth and welfare a quantitative analysis based on a calibrated version of the model reveals that these effects are substantial and of the same order of magnitude as the effects of distortionary income taxation the analysis further suggests that government sponsored severance payments to displaced workers increase growth and welfare even if these payments have to be e nanced through distortionary income taxation

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

the macroeconomic implications of rising wage inequality in the united states in recent decades american workers have faced a rising college premium a narrowing gender gap and increasing wage volatility this paper explores the quantitative and welfare implications of these changes the framework is an incomplete markets life cycle model in which individuals choose education intrafamily time allocation and savings given the observed history of the u s wage structure the model replicates key trends in cross sectional inequality in hours worked earnings and consumption recent cohorts enjoy welfare gains on average as higher relative wages for college graduates and for women translate into higher educational attainment and a more even division of labor within the household

are earnings inequality and mobility overstated the impact of non classical measurement error abstract measures of inequality and mobility based on self reported earnings reflect attributes of both the joint distribution of earnings across time and the joint distribution of measurement error and earnings while classical measurement error would increase measures of inequality and mobility there is substantial evidence that measurement error in earnings is not classical in this paper we present the analytical links between nonclassical measurement error and some summary measures of inequality and mobility the empirical importance of nonclassical measurement error is explored using the survey of income and program participation sipp matched to tax records we find that the effects of nonclassical measurement error are large however these nonclassical effects are largely offsetting when estimating mobility as measured by the intertemporal correlation in earnings as a result sipp estimates of the correlation are similar to estimates based on tax records though sipp estimates of inequality

insurance and opportunities the welfare implications of rising wage dispersion this paper develops a series of heterogeneous agents economies in order to characterize analytically the welfare implications of changes in the uncertainty in individual labor productivity we perform two types of welfare calculations first we compute the welfare consequences of a rise in labor market risk given a particular asset market structure complete markets incomplete markets autarky second we compute the expected gain from completing markets starting from autarky or incomplete markets for a given level of wage dispersion we are able to derive intuitive closed form expressions for these welfare eects which depend only on preference parameters and the size of the change in wage dispersion a higher level of productivity dispersion has always two eects it tends to reduce welfare in presence of partial insurance but it also tends to improve production opportunities in presence of flexible labor supply we can separate analytically the insurance and the opportunity components we quantify the welfare consequences of the rise in wage inequality observed in the united states over the past three decades as roughly 3 of lifetime consumption moreover we calculate that completing the asset markets given the current level of inequality would lead to a welfare improvement equivalent to 35 of lifetime consumption

consumption inequality and income uncertainty this paper places the debate over using consumption or income in studies of inequality growth in a formal intertemporal setting it highlights the importance of permanent and transitory income uncertainty in the evaluation of growth in consumption inequality we derive conditions under which the growth of variances and covariances of income and consumption can be used to separately identify the growth in the variance of permanent and transitory income shocks household data from britain for the period 1968 1992 are used to show a strong growth in transitory inequality toward the end of this period while younger cohorts are shown to face significantly higher levels of permanent inequality

tax and education policy in a heterogeneous agent economy what levels of redistribution maximize growth and efficiency this paper studies the effects of progressive income taxes and education finance in a dynamic heterogeneous agent economy such redistributive policies entail distortions to labor supply and savings but also serve as partial substitutes for missing credit and insurance markets the resulting tradeoffs for growth and efficiency are explored both theoretically and quantitatively in a model that yields complete analytical solutions progressive education finance always leads to higher income growth than taxes and transfers but at the cost of lower insurance overall efficiency is assessed using a new measure that properly reflects aggregate resources and idiosyncratic risks but unlike a standard social welfare function does not reward equality per se simulations using empirical parameter estimates show that the efficiency costs and benefits of redistribution are generally of the same order of magnitude resulting in plausible values for the optimal rates aggregate income and aggregate welfare provide only crude lower and upper bounds around the true efficiency tradeoff

consumption smoothing in island economies can public insurance reduce welfare abstract in this paper we study the effects of certain types of public compulsory insurance arrangements for aggregate shocks on private allocations in environments with limited commitment we show that this type of insurance can improve the wellbeing of private situations but it can also deteriorate it we also describe how different characteristics of the environment affect the role of public insurance using data on the mexican progresa program we document the impact that some government programs have in crowding out private transfers

the sensitivity of consumption to transitory income estimates from panel data on households we investigate the stochastic relation between income and consumption specifically consumption of food within a panel of about 2 000 households our major findings are 1 consumption responds much more strongly to permanent than to transitory movements of income 2 the response to transitory income is nonetheless clearly positive 3 a simple test independent of our model of consumption rejects a central implication of the pure life cycle permanent income hypothesis the observed covariation of income and consumption is compatible with pure life cycle permanent income behavior on the part of80 percent of families and simple proportionality of consumption and income among the remaining 20 percent as a general matter our findings support the view that families respond differently to different sources of income variations in particular temporary income tax policies have smaller effects on consumption than do other more permanent changes in income of the same magnitude this abstract was borrowed from another version of this item

the neoclassical growth model with heterogeneous quasi geometric consumers this paper investigates how the assumption of quasi geometric hyperbolic discounting affects the distributional implications of the standard one sector neoclassical growth model with infinitely lived heterogeneous agents the agents are subject to idiosyncratic shocks and face borrowing constraints we confine attention to an interior markov recursive equilibrium the consequence of quasi geometric discounting is that the effective discount factor of an agent is not a constant but an endogenous variable which depends on the agent s current state we show both analytically and by simulation that this new feature can significantly affect the distributional implications of the neoclassical growth model

consumption and labor supply with partial insurance an analytical framework we develop a model with partial insurance against idiosyncratic wage shocks to quantify risk sharing closed form solutions are obtained for equilibrium allocations and for moments of the joint distribution of consumption hours and wages we prove identification and demonstrate how labor supply data are informative about risk sharing the model estimated with us data over the period 1967 2006 implies that i 39 percent of permanent wage shocks pass through to consumption ii the share of wage risk insured increased until the early 1980s and iii preference heterogeneity is important in accounting for observed dispersion in consumption and hours jel e21 e23 e31 e52

the welfare cost of inflation under imperfect insurance abstract this paper examines the welfare cost of inflation in an economy where agents hold money in order to smooth consumption in the face of income variability for which there is no insurance the findings indicate that for the type of economies considered here the area under the empirical money demand curve is a poor measure of the welfare cost of inflation this area accounts for only one fourth of the true costs in the case of 5 inflation

consumption puzzles and precautionary savings abstract when marginal utility is convex agents accumulate savings as a precautionary measure against labor income eventualities this paper shows that precautionary savings can go a long way in making the excess growth excess smoothness and excess sensitivity features of consumption consistent with the stochastic processes of labor income observed in the u s at the microeconomic level

uncertainty persistence and heterogeneity a panel data perspective the purpose of this paper is to review newly developed identification and estimation tools that are relevant for the analysis of dynamic dependence structures of income risk i present an application to nonlinear permanent transitory models of household income using data from the panel study of income dynamics psid but the empirical approach is more generally applicable household income processes are of interest because the size of shocks the nature of their persistence and crosshousehold heterogeneity are all important to understand how income inequality varies with age and cohort and how it translates into consumption inequality i argue that going from an econometrics of autocovariances to an econometrics of flexible distributions is feasible and has the potential to reveal richer aspects of risk for example nonlinear persistence of unusual shocks jel c23 d31 d12

a simple test of consumption insurance are consumers effectively insured against idiosyncratic shocks to income or wealth either by formal institutions such as charities private insurance and government programs or by informal mechanisms such as gifts and loans from relatives friends and neighbors under full insurance consumption growth should be cross sectionally independent of idiosyncratic variables that are exogenous to consumers this proposition is tested by cross sectional regressions of consumption growth on a variety of exogenous variables full insurance is rejected for long illness and involuntary job loss but not for spells of unemployment loss of work due to strike and an involuntary move

labor supply flexibility and portfolio choice in a life cycle model abstract this paper examines the effect of the labor leisure choice on portfolio and consumption decisions over an individual s life cycle the model incorporates the fact that individuals may have considerable flexibility in varying their work effort including their choice of when to retire given this flexibility the individual simultaneously determines optimal levels of current consumption labor effort and an optimal financial investment strategy at each point in his life cycle we show that labor and investment choices are intimately related the ability to vary labor supply ex post induces the individual to assume greater risks in his investment portfolio ex ante

the wealth distribution in bewley economies with capital income risk abstract we study the wealth distribution in bewley economies with idiosyncratic capital income risk we show analytically that under rather general conditions on the stochastic structure of the economy a unique ergodic distribution of wealth displays a fat tail

risk sharing in private information models with asset accumulation explaining the excess smoothness of consumption we study testable implications for the dynamics of consumption and income of models in which first best allocations are not achieved because of a moral hazard problem with hidden saving we show that in this environment agents typically achieve more insurance than that obtained under self insurance with a single asset consumption allocations exhibit excess smoothness as found and defined by campbell and deaton 1989 we argue that excess smoothness in this context is equivalent to a violation of the intertemporal budget constraint considered in a bewley economy with a single asset we also show parameterizations of our model in which we can obtain a closed form solution for the efficient insurance contract and where the excess smoothness parameter has a structural interpretation in terms of the severity of the moral hazard problem we present tests of excess smoothness applied to u k microdata and constructed using techniques proposed by hansen roberds and sargent 1991 to test the intertemporal budget constraint our theoretical model leads us to interpret them as tests of the market structure faced by economic agents we also construct a test based on the dynamics of the cross sectional variances of consumption and income that is in a precise sense complementary to that based on hansen roberds and sargent 1991 and that allows us to estimate the same structural parameter the results we report are consistent with the implications of the model and are internally coherent

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

labor market trends and the changing value of time abstract during the past two decades households experienced increases in their average wages and expenditures alongside with divergent trends in their wages expenditures and time allocation we develop a model with incomplete asset markets and household heterogeneity in market and home technologies and preferences to account for these labor market trends and assess their welfare consequences using micro data on expenditures and time use we identify the sources of heterogeneity across households document how these sources have changed over time and perform counterfactual analyses given the observed increase in leisure expenditures relative to leisure time and the complementarity of these inputs in leisure technology we infer a significant increase in the average productivity of time spent on leisure the increasing productivity of leisure time generates significant welfare gains for the average household and moderates negative welfare effects from the rising dispersion of expenditures and time allocation across households

from earnings inequality to consumption inequality this paper studies the paths from inequality in earnings to inequality in household consumption we show that careful study of the evolution of the variances and covariances of earnings and consumption within cohorts across time can identify permanent and transitory shocks we present an application to the evolution of inequality in the united kingdom we extend previous results to recognise separate earnings of partners in couples

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

the risk free rate in heterogeneous agent incomplete insurance economies abstract why has the average real risk free interest rate been less than one percent the question is motivated by the failure of a class of calibrated representative agent economies to explain the average return to equity and risk free debt i construct an economy where agents experience uninsurable idiosyncratic endowment shocks and smooth consumption by holding a risk free asset i calibrate the economy and characterize equilibria computationally with a borrowing constraint of one year s income the resulting risk free rate is more than one percent below the rate in the comparable representative agent economy

optimal taxation in a habit formation economy abstract this paper studies habit formation in consumption preferences in a dynamic mirrlees economy we derive optimal labor and savings wedges based on a recursive approach we show that habit formation creates a motive for subsidizing labor supply and savings in particular habit formation invalidates the well known no distortion at the top result we demonstrate that the theoretical findings are quantitatively important in a parametrized life cycle model average labor and savings wedges fall by more than one third compared with the case of time separable preferences

human capital and earnings distribution dynamics abstract earnings heterogeneity plays a crucial role in modern macroeconomics we document that mean earnings and measures of earnings dispersion and skewness all increase in us data over most of the working life cycle for a typical cohort as the cohort ages we show that i a human capital model can replicate these properties from the right distribution of initial human capital and learning ability ii differences in learning ability are essential to produce an increase in earnings dispersion over the life cycle and iii differences in learning ability account for the bulk of the variation in the present value of earnings across agents these findings emphasize the need to further understand the role and origins of initial conditions

optimal taxation in a limited commitment economy this paper studies optimal ramsey taxation when risk sharing in private insurance markets is imperfect due to limited enforcement in a limited commitment economy there are externalities associated with capital and labor because individuals do not take into account that their labor and saving decisions aect aggregate supply wages

heterogeneous life cycle profiles income risk and consumption inequality was the increase in income inequality in the us due to permanent shocks or merely to an increase in the variance of transitory shocks the implications for consumption and welfare depend crucially on the answer to this question we use consumer expenditure survey cex repeated cross section data on consumption and income to decompose idiosyncratic changes in income into predictable life cycle changes transitory and permanent shocks and estimate the contribution of each to total inequality our model fits the joint evolution of consumption and income inequality well and delivers two main results first we find that permanent changes in income explain all of the increase in inequality in the 1980s and 1990s second we reconcile this finding with the fact that consumption inequality did not increase much over this period our results support the view that many permanent changes in income are predictable for consumers even if they look unpredictable to the econometrician consistent with models of heterogeneous income profiles

income variance dynamics and heterogeneity recent theoretical work has shown the importance of measuring microeconomic uncertainty for models of both general and partial equilibrium under imperfect insurance in this paper the assumption of i i d income innovations used in previous empirical studies is removed and the focus of the analysis is placed on models for the conditional variance of income shocks which is related to the measure of risk emphasized by the theory we first discriminate amongst various models of earnings determination that separate income shocks into idiosyncratic transitory and permanent components we allow for education and time specific differences in the stochastic process for earnings and for measurement error the conditional variance of the income shocks is modelled as a parsimonious arch process with both observable and unobserved heterogeneity the empirical analysis is conducted on data drawn from the 1967 1992 panel study of income dynamics we find strong evidence of sizeable arch effects as well as evidence of unobserved heterogeneity in the variances

solving an incomplete markets model with a large cross section of agents abstract this paper shows that perturbation methods can be applied to a dsge model with incomplete markets and a finite but arbitrarily large number of heterogeneous agents we develop a simple but general solution technique that handles many state and choice variables for each agent and thus has an extremely high dimensional state space the method is based on perturbations around a point at which the solution is known the novel idea is to exploit the symmetry of the problem to overcome the curse of dimensionality we use the analysis to demonstrate the impact of heterogeneity on macroeconomic quantities and the pricing of risk furthermore we set our technique apart from standard methods used in the literature

methods versus substance measuring the effects of technology shocks abstract calibration and modern bayesian estimation methods for a neoclassical stochastic growth model are applied to make the case that the identification of key parameters rather than quantitative methodologies per se is responsible for empirical findings for concreteness the model is used to measure the contributions of technology shocks to the business cycle fluctuations of hours worked and output along the way new insights are provided in the parameter identification associated with likelihood based estimation the sensitivity of likelihood based estimation to the choice of structural shocks is assessed and bayesian model averaging is used to aggregate findings obtained from different dsge model specifications