what explains household stock holdings abstract this is an empirical study of the determinants of stock holdings using data from the us survey of consumer finances from 1992 to 2001 there is a great heterogeneity in the way households form their portfolios stock ownership is positively correlated with various measures of wealth age retirement savings and having sought financial advice it is negatively correlated with holdings of alternative risky investments such as investments in private businesses and with the willingness to undertake non financial investments in the future while we can predict reasonably well who holds stocks we have less predictive power about the share of stocks owned by those who hold positive amounts

optimal consumption portfolio policies a convergence from discrete to continuous time models abstract we establish a convergence of optimal intertemporal consumption and portfolio policies from a sequence of discrete time multivariate and multinomial models to a continuous time multi dimensional diffusion model

optimal consumption and investment with transaction costs and multiple risky assets we consider the optimal intertemporal consumption and investment policy of a constant absolute risk aversion cara investor who faces fixed and proportional transaction costs when trading multiple risky assets we show that when asset returns are uncorrelated the optimal investment policy is to keep the dollar amount invested in each risky asset between two constant levels and upon reaching either of these thresholds to trade to the corresponding optimal targets an extensive analysis suggests that transaction cost is an important factor in affecting trading volume and that it can significantly diminish the importance of stock return predictability as reported in the literature this paper studies the optimal intertemporal consumption and investment policy of an investor with a constant absolute risk aversion cara preference and an infinite horizon the investor can trade in one risk free asset and n 1 risky assets in contrast to the standard setting the investor faces both fixed and proportional transaction costs in trading any of these risky assets in the absence of transaction costs and when risky asset prices follow geometric brownian motions the optimal investment policy is to keep a constant dollar amount in each risky asset as shown by merton 1971 this trading strategy requires continuous trading in all the risky assets in addition the optimal consumption is affine in the total wealth in the presence of transaction costs however trading continuously in a risky asset would incur infinite transaction costs therefore risky assets are traded only infrequently in this case the literature on optimal consumption and investment with multiple risky assets subject to transaction costs is limited leland 2000 examines a multiasset investment fund that is subject to transaction costs and capital gains taxes under the assumption that the fund has an exogenous target for each risky asset he develops a relatively simple numerical procedure to compute the no transaction region akian menaldi and sulem 1996 consider an optimal consumption and investment problem with proportional transaction costs for

portfolio choice under transitory price impact abstract we consider a portfolio optimization problem for a short term investor who faces an illiquid stock market the illiquidity of this market results from a transitory price impact that is captured by the transaction costs that are convex in the number of shares traded by an investor the linear component in these costs defines a no trading zone while the nonlinear component does not allow trading the stock at an arbitrary rate the portfolio choice problem is solved when the stock path is continuous and when the stock may crash we find that an economy could be in states where the conditional liquidity premium is of the same order of magnitude as the historical risk premium of the stock market if the illiquid stock undergoes crashes then in many states an investor demands a premium for crashes that is much higher than that in the liquid market finally we study the shape of the no trading zone when the nonlinearity in the transitory price impact is strong or moderate we find that this shape is significantly different from that when the transitory price impact is linear

an evaluation of the life cycle effects of minimum pensions on retirement behavior in this paper we explore the effects of the minimum pension program on welfare and retirement in spain this is done with a stylized life cycle model which provides a convenient analytical characterization of optimal behavior we use data from the spanish social security to estimate the behavioral parameters of the model and then simulate the changes induced by the minimum pension in aggregate retirement patterns the impact is substantial there is a threefold increase in retirement at 60 the age of first entitlement with respect to the economy without minimum pensions and total early retirement before or at 60 is almost 50 larger copyright 2007 john wiley sons ltd

monetary shocks in models with inattentive producers we study models where prices respond slowly to shocks because firms are rationally inattentive producers must pay a cost to observe the determinants of the current profit maximizing price and hence observe them infrequently to generate large real effects of monetary shocks in such a model the time between observations must be long and or highly volatile previous work on rational inattentiveness has allowed for observation intervals that are either constant but long e g caballero 1989 or reis 2006 or volatile but short e g reis s 2006 example where observation costs are negligible but not both in these models the real effects of monetary policy are small for realistic values of the duration between observations we show that non negligible observation costs produce both of these effects intervals between observations are infrequent and volatile this generates large real effects of monetary policy for realistic values of the average time between observations

a further look at household portfolio choice and health status abstract this paper investigates the effect of changes in health status on household financial wealth and financial portfolio choice it is shown that the impact of health events on household financial and non financial wealth is asymmetric a diagnosis of a new disease leads to a larger decrease in financial wealth than in non financial wealth moreover we find that the puzzle pertaining to the relationship between health status and portfolio choice discussed in the extant literature generally disappears after controlling for differences in the amount of financial assets held by healthy and sick people the results suggest that the effect of changes in health status on household financial portfolios is indirect a health shock significantly reduces household total financial wealth in turn leading households to restructure the composition of their financial assets

optimal inattention to the stock market with information costs and transactions costs recurrent intervals of inattention to the stock market are optimal if consumers incur a utility cost to observe asset values when consumers observe the value of their wealth they decide whether to transfer funds between a transactions account from which consumption must be financed and an investment portfolio of equity and riskless bonds transfers of funds are subject to a transactions cost that reduces wealth and consists of two components one is proportional to the amount of assets transferred and the other is a fixed resource cost because it is costly to transfer funds the consumer may choose not to transfer any funds on a particular observation date in general the optimal adjustment rule including the size and direction of transfers and the time of the next observation is state dependent surprisingly unless the fixed resource cost of transferring funds is large the consumer s optimal behavior eventually evolves to a situation with a purely time dependent rule with a constant interval of time between observations this interval of time can be substantial even for tiny observation costs when this situation is attained the standard consumption euler equation holds between observation dates if the consumer is sufficiently risk averse

price barriers and the dynamics of asset prices in equilibrium a price barrier is a price level at which a large number of investors either buy or sell securities we analyze the dynamics of asset prices in an economy in which price barriers exist our analysis suggests that asset prices and volatility can exhibit jumps when the price barrier is reached interestingly the market s anticipation of future trades can influence prices in the opposite direction from what one might expect for example when multiple barriers exist stock prices can be inflated rather than depressed in the proximity of an anticipated stock sale

elasticity of intertemporal substitution in consumption in the presence of inertia empirical evidence from a natural experiment this paper estimates the elasticity of intertemporal substitution in consumption by exploiting a natural experiment provided by a change in the indian banking legislation the new legislation authorized banks to offer higher interest rates on deposits to citizens above 60 years of age we find evidence that households exhibit inertia in reoptimization and are sensitive to the timing of the actual change in the interest rate households do not respond to the predictable changes in future interest rates induced by the change in the legislation we incorporate this and estimate the to be approximately equal to 2 2 this paper was accepted by amit seru finance

portfolio choice with puts evidence from variable annuities this study investigated the asset allocation behavior of individuals who select an out of the money long dated longevity put option on their investment funds the asset allocations of these people within their variable annuity subaccounts are 5 30 percent more risky than the allocations of those who do not choose this protection investors who do not choose the longevity put option follow the classic life cycle age phased reduction in equity a rudimentary model of utility maximizing behavior is suggested that justifies the increased allocation to risk as long as the investor understands the payoff structure of the longevity put and is willing and able to exercise the annuity option if and when it matures in the money

social security and the retirement decision the effect of social security and private pensions on individual retirement decisions is modeled relaxing in turn three commonly maintained assumptions perfect capital markets actuarial fairness and certain lifetimes which together imply that there is no effect in each case raising the contribution level can cause systematic changes of either sign in general in individual retirement decisions for social security the effects associated with forced saving and deviations from actuarial fairness probably tend to advance retirement but those effects that arise solely from the insurance aspect of social security and private pensions are ambiguous in sign owing to the presence of a substitution effect that tends to delay retirement because the insurance benefits can be fully realized only by working longer

optimal portfolio choice for long horizon investors with nontradable labor income this paper examines how risky labor income and retirement affect optimal portfolio choice with idiosyncratic labor income risk the optimal allocation to stocks is unambiguously larger for employed investors than for retired investors consistent with the typical recommendations of investment advisors increasing idiosyncratic labor income risk raises investors willingness to save and reduces their stock portfolio allocation towards the level of retired investors positive correlation between labor income and stock returns has a further negative effect and can actually reduce stockholdings below the level of retired investors financial advisors typically recommend that their customers invest more in stocks than in safe assets when they are working and to shift their investments towards safe assets when they retire jagannathan and kocherlakota 1996 malkiel 1996 by contrast the standard academic models of portfolio choice merton 1969 1971 samuelson 1969 show that retirement is irrelevant for portfolio decisions if investment opportunities are constant and human capital is tradable in this case the fraction of wealth optimally invested in risky assets should be constant over the lifetime of an individual recent research building on the pioneering work by merton 1971 shows that time varying investment opportunities result in portfolio rules with an intertemporal hedging component whose magnitude depends on the investment horizon of the investor kim and omberg 1996 balduzzi and lynch 1997 brennan schwartz and lagnado 1997 brandt 1999 campbell and viceira 1999 2001 barberis 2000 with time variation in investment opportunities retirement and death play an instrumental role as events that exogenously fix the individual s investment horizon more importantly retirement also marks the time at which individuals stop working and thereafter must live off their lifetime savings and possibly transfers from this perspective retirement matters for portfolio choice

who should buy long term bonds according to conventional wisdom long term bonds are appropriate for conservative long term investors this paper develops a model of optimal consumption and portfolio choice for infinite lived investors with recursive utility who face stochastic interest rates solves the model using an approximate analytical method and evaluates conventional wisdom as risk aversion increases the myopic component of risky asset demand disappears but the intertemporal hedging component does not conservative investors hold assets to hedge the risk that real interest rates will decline long term inflation indexed bonds are most suitable for this purpose but nominal bonds may also be used if inflation risk is low

asset price dynamics and infrequent feedback trades this article combines the continuous arrival of information with the infrequency of trades and investigates the effects on asset price dynamics of positive and negative feedback trading specifically we model an economy where stocks and bonds are traded by two types of agents speculators who maximize expected utility and feedback traders who mechanically respond to price changes and infrequently submit market orders we show that positive feedback strategies increase the volatility of stock returns and the response of stock prices to dividend news conversely the presence of negative feedback traders makes stock returns less volatile and prices less responsive to dividends

life cycle portfolio choice with additive habit formation preferences and uninsurable labor income risk this article explores the implications of additive and endogenous habit formation preferences in the context of a life cycle model of an investor who has stochastic uninsurable labor income to solve the model i analytically derive the habit wealth feasibility constraints and show that they depend on the worst possible path of future labor income and on the habit strength but not on the probability of the worst income when there is only a slim chance of a severe income shock the model implies much more conservative portfolios the model also predicts that for some low to moderately wealthy households the portfolio share allocated to stocks increases with wealth because of this feature the model can generate more conservative portfolios for younger than for middle aged households the effects of habits on portfolio choice are robust to income smoothing through borrowing or flexible labor supply one controversial finding is that for high values of the habit strength parameter usually required for the resolution of asset pricing puzzles in general equilibrium the life cycle model predicts counterfactually high wealth accumulation jel g11 g12 copyright 2007 oxford university press

sticky information in general equilibrium this paper develops and analyzes a general equilibrium model with sticky information the only rigidity in goods labor and financial markets is that agents are inattentive sporadically updating their information sets when setting prices wages and consumption after presenting the ingredients of such a model the paper develops an algorithm to solve this class of models and uses it to study the model s dynamic properties it then estimates the parameters of the model using u s data on five key macroeconomic time series it finds that information stickiness is present in all markets and is especially pronounced for consumers and workers variance decompositions show that monetary policy and aggregate demand shocks account for most of the variance of inflation output and hours jel e30 e10

new evidence on pensions social security and the timing of retirement using a unique dataset that links the economic and demographic information of households with the details of their pension formulas i estimate the combined effect of social security and pension benefits on the probability of retirement in a cross section of the population near retirement age the accrual rate of retirement wealth is shown to be a significant determinant of the probability of retirement simulations of extensions in pension coverage comparable to those that occurred in the early postwar period can account for one fourth of the contemporaneous decline in labor force participation rates 1998 elsevier science s a all rights reserved

continuous time methods in finance a review and an assessment i survey and assess the development of continuous time methods in finance during the last 30 years the subperiod 1969 to 1980 saw a dizzying pace of development with seminal ideas in derivatives securities pricing term structure theory asset pricing and optimal consumption and portfolio choices during the period 1981 to 1999 the theory has been extended and modified to better explain empirical regularities in various subfields of finance this latter subperiod has seen significant progress in econometric theory computational and estimation methods to test and implement continuous time models capital market frictions and bargaining issues are being increasingly incorporated in continuous time theory the roots of modern continuous time methods in finance can be traced back to the seminal contributions of merton 1969 1971 1973b in the late 1960s and early 1970s merton 1969 pioneered the use of continuous time modeling in financial economics by formulating the intertemporal consumption and portfolio choice problem of an investor in a stochastic dynamic programming setting merton 1973b also showed how such a framework can be used to develop equilibrium asset pricing implications thereby significantly extending the asset pricing theory to richer dynamic settings and expanding the scope of applications of continuous time methods to study problems in financial economics 1 within a span of about 30 years from the publication of merton s inf luential papers continuous time methods have become an integral part of financial economics indeed in certain core areas in finance such as e g asset pricing derivatives valuation term structure theory and portfolio selection continuoustime methods have proved to be the most attractive way to conduct research and gain economic intuition the continuous time approach in these areas has produced models with a rich variety of testable implications the econometric theory for testing continuous time models has made rapid strides in the last decade and has thus kept pace with the impressive progress on the theoretical front one hopes that the actual empirical investigations and estimation using the new procedures will follow suit soon

portfolio choice in the presence of personal illiquid projects personal projects such as a private business or the purchase of a home influence individuals portfolio choice we conduct a theoretical analysis of this influence when financial assets are required to provide liquidity to personal projects due to this liquidity consideration individuals behave in a more risk averse fashion when there is a large penalty for discontinuing or underinvesting in the final stages of the projects in addition using data from the 1995 survey of consumer finances we find that households that are saving to invest in their own businesses or in their own homes indeed have significantly safer financial portfolios a large portion of private assets are invested in personal illiquid projects these are projects that must be partly self financed and are costly to sell according to the 1995 survey of consumer finances scf residential housing and capital invested in unincorporated businesses account for 41 2 percent and 19 1 percent respectively of household wealth in this paper we study the impact of these personal illiquid projects on individuals portfolios of financial assets personal projects influence portfolio choice in two ways first financial assets can be used to provide diversification against bad outcomes of personal projects this interaction is well recognized in the literature as it emanates from standard portfolio theory second financial assets can be used to provide liquidity to personal projects when the timing of investment in these projects is important this latter interaction is the focus of our paper we show that it helps explain why individuals particularly young investors and entrepreneurs have larger than expected holdings of safe financial assets in the financial planning literature young investors are advised to hold a larger share of risky assets in their financial portfolios in order to capture the superior expected return of these assets as investors grow older they are advised to gradually reduce their holdings of risky assets jagannathan and kocherlakota 1996 show that this advice is economically sound as long as the investor s human wealth is relatively uncorrelated with stock returns

the demand of liquid assets with uncertain lumpy expenditures abstract we consider an inventory model for a liquid asset where the per period net expenditures have two components one that is frequent and small and another that is infrequent and large we give a theoretical characterization of the optimal management of liquid asset as well as of the implied observable statistics we use our characterization to interpret some aspects of households currency management in austria as well as the management of demand deposits by a large sample of italian investors

limited stock market participation among renters and homeowners the stock market participation rate among homeowners is twice as high as among renters this paper builds a life cycle portfolio choice model with endogenous housing tenure choice a stylized form

pension design with a large informal labor market evidence from chile this article investigates the fiscal and welfare trade offs involved in designing a pension system when workers can avoid contributing by working informally using a life cycle model of labor supply and saving decisions i structurally estimate preferences and earnings opportunities in the formal and informal sectors using data on chilean households i find limited support for formal jobs rationing instead mandatory pension contributions significantly encourage informality policy experiments show that chile could lower minimum pension spending by 23 while guaranteeing the same income to retirees if the minimum pension s implicit tax rate was increased to 60

a sparsity based model of bounded rationality this article defines and analyzes a sparse max operator which is a less than fully attentive and rational version of the traditional max operator the agent builds as economists do a simplified model of the world which is sparse considering only the variables of first order importance his stylized model and his resulting choices both derive from constrained optimization still the sparse max remains tractable to compute moreover the induced outcomes reflect basic psychological forces governing limited attention the sparse max yields a behavioral version of basic chapters of the microeconomics textbook consumer demand and competitive equilibrium i obtain a behavioral version of marshallian and hicksian demand arrow debreu competitive equilibrium the slutsky matrix the edgeworth box roy s identity and so on the slutsky matrix is no longer symmetric nonsalient prices are associated with anomalously small demand elasticities because the consumer exhibits nominal illusion in the edgeworth box the offer curve is a two dimensional surface rather than a one dimensional curve as a result different aggregate price levels correspond to materially distinct competitive equilibria in a similar spirit to a phillips curve the arrow debreu welfare theorems typically do not hold this framework provides a way to assess which parts of basic microeconomics are robust and which are not to the assumption of perfect maximization jel codes d01 d03 d11 d51

optimal inattention to the stock market inattentive agents update their information sporadically and thus respond belatedly to news we generate optimally inattentive behavior by assuming that to observe the value of his investment portfolio the consumer must pay a cost that is proportional to the portfolio s contempo raneous value it is optimal for the consumer to check his investment portfolio at equally spaced points in time consuming from a riskless trans actions account in the interim the riskless transactions account that finances consump tion guarantees that funds are never unwittingly exhausted we show that the optimal interval of time between consecutive observations of the value of the portfolio is the unique positive solution to a nonlinear equation quantitatively even a small observation cost one basis point of wealth implies a substantial eight month decision interval under conventional parameter values

owner occupied housing life cycle implications for the household portfolio empirical work on portfolio composition over the life cycle indicates that the portfolio share devoted to risky assets has a hump shaped profile with respect to age that is as households accumulate wealth they tend to invest an increasing fraction of their wealth in risky assets only at a very advanced age do households on average reduce the share of their portfolio held in risky assets the hump shaped age profile of risky asset holding has proven difficult to reconcile with standard models of portfolio allocation in this paper we incorporate owner occupied housing in a model of household consumption and portfolio allocation instead of assuming that the household can borrow and lend without limit at a riskless interest rate we assume that the household s portfolio allocation decision is subject to a collateral constraint the household can borrow only in the form of a mortgage and the size of the mortgage cannot exceed the house value solving for the optimal portfolios we show that the collateral constraint induces a hump shaped profile in the optimal share of stocks in the portfolio the empirical work supports our assertion that the apparent age effect on portfolio composition arises because the age of the household head acts as a proxy for the housing collateral effect new developments in housing research

monetary shocks in models with observation and menu costs we study economies where price stickiness arises due to the simultaneous presence of both menu and information costs we identify the relative importance of these costs using firm s survey data and analyze the response of prices and output following a permanent unexpected monetary shock for a given frequency of price adjustment we find that the information friction significantly amplifies the real effect of the shock when the shock is small or when it is not known by firms instead when the shock is large and known to firms the flexibility of prices increases and the real effects gradually vanish

investment dynamics with fixed capital adjustment cost and capital market imperfections this paper examines the implications of financing frictions on capital stocks and on capital accumulation in the presence of non convex costs of adjusting the capital stock in this setup finance has an influence on both the level of capital and the timing of investment finance and productivity are complements and finance influences investment the strongest when firms wish to significantly adjust capital for fundamental reasons these theoretical considerations are confronted with uk data while finance is mostly irrelevant for long term capital decision the short run investment function shows a significant impact of finance which is also strongest for strong fundamental investment incentives

transactions costs and portfolio choice in a discrete continuous time setting abstract this paper makes the following observation concerning a new formulation of the consumption and portfolio choice model of merton 1971 with transaction costs suppose an investor observes his or her current wealth only when making a transaction that transactions are costly and that decisions to transact can be made at any time based on all current information if at each transaction the agent is charged a fixed fraction of current portfolio value an optimal policy exists and the optimal interval of time between transactions is fixed independent of time and current wealth

arbitrage with fixed costs and interest rate models in this paper we study securities market models with fixed costs we characterize the absence of arbitrage opportunities and we provide fair pricing rules we then apply these results to extend some popular interest rate and option pricing models which present arbitrage opportunities in the absence of fixed costs in particular we prove that the quite striking result obtained by dybvig ingersoll and ross 1996 which asserts that under the assumption of absence of arbitrage long zero coupon rates can never fall is no longer true in models with fixed costs even arbitrarily small ones for instance models where the long term rate follows a diffusion process are arbitrage free in the presence of fixed costs including arbitrarily small ones we also rationalize models with partially absorbing or reflecting barriers on the price processes in particular we propose a version of the cox ingersoll and ross 1985 model which as in longstaff 1992 produces yield curves with realistic humps but does not assume an absorbing barrier for the short term rate this is made possible by the presence of even arbitrarily small fixed costs

life cycle asset allocation with annuity markets abstract this paper derives the optimal consumption and portfolio choice pattern over the life cycle for households facing uninsurable labor income risk ruin risk stochastic capital markets and uncertain lifetime our model posits a dynamic utility maximizer with crra and epstein zin preferences who has access to liquid stocks bonds and illiquid life annuities we show that a considerable fraction of wealth is gradually annuitized until retirement and beyond to skim the mortality credit the remaining liquid wealth is mainly invested in stocks to compensate for riskless investment in life annuities the model allows us to assess the economic importance of common explanations for the empirically low annuity demand by analyzing participations rates annuitization fractions and welfare effects

asset returns with transactions costs and uninsured individual risk abstract we explore whether incorporating an explicit motive for holding liquid assets within an equilibrium asset pricing model helps explain the following features of asset returns and turnover in the post war u s economy i the low risk free real interest rate ii the large spread between returns on liquid assets and stocks and iii the greater transaction velocity of liquid assets relative to stocks we introduce a demand for liquid assets by adding uninsured individual risk together with differential costs of trading securities numerical simulations attempting to match the return data generate a ratio of liquid assets to income considerably below observed levels

social security liquidity and early retirement abstract this paper investigates the effect of social security on retirement decisions it argues that it is important to take realistic account of how recipients evaluate potential benefit flows the paper presents a simple retirement model in which liquidity constraints prompt individuals to use higher than market discount rates in evaluating future pension benefits as a consequence even an apparently actuarially fair early retirement benefit could on average discourage continued work using data on individual retirement decisions i find support for the argument that this phenomenon contributes to some of the observed increase in early retirement

small cues change savings choices we present evidence from randomized field experiments that 401 k savings choices are significantly affected by one to two sentence anchoring goal setting or savings threshold cues embedded in emails sent to employees about their 401 k plan even though these cues contain little to no marginal information cues that make high savings rates salient increased 401 k contribution rates by up to 2 9 of income in a pay period and cues that make low savings rates salient decreased 401 k contribution rates by up to 1 4 of income in a pay period cue effects persist between two months and a year after the email

the effects of health insurance and self insurance on retirement behavior this paper provides an empirical analysis of the effects of employer provided health insurance medicare and social security on retirement behavior using data from the health and retirement study we estimate a dynamic programming model of retirement that accounts for both saving and uncertain medical expenses our results suggest that medicare is important for understanding retirement behavior and that uncertainty and saving are both important for understanding the labor supply responses to medicare half the value placed by a typical worker on his employer provided health insurance is the value of reduced medical expense risk raising the medicare eligibility age from 65 to 67 leads individuals to work an additional 0 074 years over ages 60 69 in comparison eliminating 2 years worth of social security benefits increases years of work by 0 076 years

an exact solution to a dynamic portfolio choice problem under transactions costs the presence of any friction in financial markets qualitatively changes the nature of the optimization problem faced by an investor it requires one to either act or do nothing an issue which of course does not arise in frictionless situations the investor considered here accumulates wealth without consuming until some terminal point in time when he consumes all his objective is to maximize the expected utility derived from that terminal consumption we postpone the terminal point far into the future to obtain a stationary portfolio rule the portfolio policy is in the form of two control barriers between which portfolio proportions are allowed to fluctuate we show how to calculate them

inattention wealth inequality and equilibrium asset prices abstract heterogeneity in planning propensity affects wealth inequality and asset prices this paper presents an economy where attentive agents plan their consumption period by period while inattentive agents plan every other period inattentive consumers face more uncertainty and trade at unfavorable prices if the only source of uncertainty is future income inattentive consumers accumulate more wealth in contrast with uncertain asset returns inattentive investors accumulate less wealth asset prices must induce attentive consumers to voluntarily bear the burden of adjusting to aggregate shocks and as a result are much more volatile than in a representative agent model with full attention

durable consumption and asset management with transaction and observation costs this paper provides a contribution to the recent growing literature on rational inattention we start by testing the implications of recent rational inattention models of asset management liquidity holdings and savings using two novel datasets some predictions of these models are at odds with the data which motivates us to introduce a new model that shifts the focus from non durable to durable consumption and features both information and adjustment costs the focus on non durable consumption which departs from the previous literature is key to improve the fit of the model the investor s behavior in our setup combines elements of what the literature refers to as state dependent and time dependent adjustments the model allows us to quantify the information and transactions costs that are consistent with observed patterns of information review and asset trades a calibration of the model shows that very small information costs are sufficient to reproduce the relatively high frequency of observation that is found in the data we test a novel prediction of the model on the relationship between assets trades and durable goods trades and find it aligned with the data

life cycle portfolio choice with liquid and illiquid financial assets abstract traditionally quantitative models that have studied households portfolio choices have focused exclusively on the different risk properties of alternative financial assets we introduce differences in liquidity across assets in the standard life cycle model of portfolio choice more precisely in our model stocks are subject to transaction costs as considered in recent macroliterature we show that when these costs are calibrated to match the observed infrequency of households trading the model is able to generate patterns of portfolio stock allocation over age and wealth that are constant or moderately increasing thus more in line with the existing empirical evidence

investment dynamics with information costs investment in physical capital at the micro level is infrequent and large or lumpy the most common explanation for this is that firms face non convex physical adjustment costs the model developed in this paper shows that information costs make investment lumpy at the micro level even in the absence of non convex adjustment costs when collecting and processing information is costly the firm optimally chooses to do it sporadically and to be inactive most of the time this behavior results in infrequent and possibly large capital adjustments the model fits plant level investment rate moments well and it also matches some higher order moments of aggregate investment rates keywords investment dynamics information costs inattentiveness lumpy investment jel classification d21 d83 d92 e22

demand for cash with intra period endogenous consumption abstract we extend the literature on the demand for money by relaxing the assumption of a constant rate of consumption although total consumption is still fixed over the period agents can choose more than one rate of consumption and cash depletion in the period to minimize the cost of money management consistent with empirical evidence we find that agents do not smooth intra period consumption instead their rate of consumption will be positively related to their cash position this positive correlation depends on the volatility of the consumption process

the risk premium and long run global imbalances this study proposes that heterogeneous household portfolio choices within a country and across countries offer an explanation for global imbalances we construct a stochastic growth multi country model in which heterogeneous agents face the following restrictions on asset trade first the degree of us equity market participation is higher than that of the rest of the world second a fraction of households in each country maintains a fixed share of equity in its portfolios in our calibrated model which matches the us net foreign asset position and the equity premium the average us household loads up more aggregate risk than the average foreign household by investing in risky assets abroad and issuing risk free assets as a result the us is compensated by a high risk premium and runs trade deficits even as a debtor country the long run average trade deficit in our model accounts for 50 of the observed us trade deficit

optimal consumption and investment with capital gains taxes this article characterizes optimal dynamic consumption and portfolio decisions in the presence of capital gains taxes and short sale restrictions the optimal decisions are a function of the investor s age initial portfolio holdings and tax basis our results capture the trade off between the diversification benefits and tax costs of trading over an investor s lifetime the incentive to rediversify the portfolio is inversely related to the size of the embedded gain and investor s age contrary to standard financial advice the optimal equity holding increases well into an investor s lifetime in our model due to the forgiveness of capital gains taxes at death taxes play an important role in the decision making process of individuals concerning their consumption and investment plans the taxation of returns on financial assets alters the benefits of saving for future consumption and thus affects the trade off between current consumption and investment moreover the ability of investors to defer the taxation of capital gains alters the relative valuation of stocks and bonds and thus affects the optimal portfolio composition of investors the deferral feature of capital gains taxes also affects the trade off investors face regarding taxes and diversification investors would like to maintain an optimally diversified portfolio over time

equilibrium asset prices with undiversifiable labor income risk abstract in a two period lucas tree economy in which ex ante identical but ex post dissimilar agents face undiversifiable labor income risk calibrating a wrong representative agent model results in overstating the equilibrium riskfree rate and in understating the equilibrium equity premium if the utility function exhibits decreasing absolute risk aversion and decreasing absolute prudence these behavioral assumptions provide as a consequence a theoretical rationale for the often advanced conjecture that nontraded risk contributes to the solution of the riskfree rate and equity premium puzzles

investment opportunities and corporate demand for lines of credit abstract the behavior of a risk neutral corporation in selection of a line of credit is modeled in a new framework where demand for credit lines by a firm arises from the stochastic arrival in continuous time of short lived opportunities to capture investment projects the firm needs speed and secrecy to capture projects before competitors the firm chooses a credit line that balances its up front commitment cost against the expected extra cost of borrowing in the spot market upon exhaustion of its credit line the firm s demanded credit line depends upon both relative pricing within the contract and the nature of the firm s growth opportunities interestingly while credit line demand is positively related to business growth prospects it is potentially negatively related to uncertainty in those prospects

learning and asset price jumps w e develop a general equilibrium model in which income and dividends are smooth but asset prices contain large moves jumps these large price jumps are triggered by optimal decisions of investors to learn the unobserved state we show that learning choice is determined by preference parameters and the conditional volatility of income process an important model prediction is that income volatility predicts future jump periods while income growth does not consistent with the model large moves in returns in the data are predicted by consumption volatility but not by consumption growth the model quantitatively captures these novel features of the data jel g00 g12 g14 d83 a prominent feature of financial markets is infrequent but large price movements jumps 1 in this article we develop a model in which income and dividends have smooth gaussian dynamics however asset prices are subject to large infrequent jumps in our model large moves in asset prices obtain from the actions of the representative agent to acquire more information about the unobserved state of the economy for a cost we show that the optimal decision to incur a cost and learn the true economic state is directly related to the level of uncertainty in the economy this implies that aggregate economic volatility as well as market volatility should predict jumps in returns we show that indeed in the data consistent with the model return jumps are predicted by consumption volatility market volatility further the implied asset price implications from our model are consistent with the key findings from parametric models about frequency and predictability of jumps as well as nonparametric jump detection analysis of barndorff nielsen and shephard 2006 based on

macroeconomic implications of early retirement in the public sector the case of brazil abstract in brazil generous public sector pensions have induced civil servants to retire on average at age 55 in this paper we assess the efficiency gains from eliminating such policy induced early retirement in a two sector overlapping generations economy we find the adverse effects of that policy are significant specifically the generosity of public sector pensions which induces civil servants to retire 5 years prematurely at age 55 rather than at age 60 is often associated with decreases in steady state output gdp of almost 3 and welfare losses in the private sector of more than 3 of consumption

mean variance econometric analysis of household portfolios we investigate households portfolio choice using a microeconometric approach derived from mean variance optimization we assume that households have heterogeneous expectations on the distribution of excess returns and that they cannot take short positions in risky assets assuming two such assets we derive an explicit solution of the model characterized by four possible portfolio regimes which are analyzed using two structural probit and tobit specifications with three latent state variables both specifications are estimated by weighted maximum likelihood on a cross section of us households drawn from the 2004 scf the tobit specification is simulated in order to evaluate the regressors effects on regime probabilities and asset demands we also assess to what extent the predicted state variables are consistent with the self reported expected returns and risk aversion elicited from the scf questionnaire copyright 2009 john wiley sons ltd

consumption smoothing and portfolio rebalancing the effects of adjustment costs abstract a household s response to income and return shocks depends on the costs of portfolio adjustment in particular the extent of portfolio rebalancing and consumption smoothing are influenced by the presence of non convex portfolio adjustment costs suppose bonds can be adjusted costlessly while adjustments to stock accounts entail adjustment costs due to these portfolio adjustment costs the household demands both stocks and bonds a household can buffer some income fluctuations without incurring adjustment costs and engage in costly portfolio rebalancing less frequently using the estimated preference parameters and portfolio adjustment costs the response to income and return shocks is nonlinear and reflects the interaction of portfolio rebalancing and consumption smoothing

the effects of health wealth and wages on labour supply and retirement behaviour this paper estimates a life cycle model of labour supply retirement and savings behaviour in which future health status and wages are uncertain individuals face a fixed cost of work and cannot borrow against future labour pension or social security income the method of simulated moments is used to match the life cycle profiles of labour force participation hours worked and assets that are estimated from the data to those that are generated by the model the model establishes that the tax structure of the social security system and pensions are key determinants of the high observed job exit rates at ages 62 and 65 removing the tax wedge embedded in the social security earnings test for individuals aged 65 and older would delay job exit by almost one year by contrast social security benefit levels health and borrowing constraints are less important determinants of job exit at older ages for example reducing social security benefits by 20 would cause workers to delay exit from the labour force by only three months

optimal price setting with observation and menu costs we study the price setting problem of a firm in the presence of both observation and menu costs in this problem the firm optimally decides when to collect costly information on the adequacy of its price an activity which we refer to as a price review upon each review the firm chooses whether to adjust its price subject to a menu cost and when to conduct the next price review this behavior is consistent with recent survey evidence documenting that firms revise prices infrequently and that only a few price revisions yield a price adjustment the goal of the paper is to study how the firm s choices map into several observable statistics depending on the level and relative magnitude of the observation vs the menu cost the observable statistics are the frequency of price reviews the frequency of price adjustments the size distribution of price adjustments and the shape of the hazard rate of price adjustments we provide an analytical characterization of the firm s decisions and a mapping from the structural parameters to the observable statistics we compare these statistics with the ones obtained for the models with only one type of cost the predictions of the model can with suitable data be used to quantify the importance of the menu cost vs the information cost we also consider a version of the model where several price adjustment are allowed between observations a form of price plans or indexation we find that no indexation is optimal for small inflation rates

infrequent rebalancing return autocorrelation and seasonality a model of infrequent rebalancing can explain specific predictability patterns in the time series and cross section of stock returns first infrequent rebalancing produces return autocorrelations that are consistent with empirical evidence from intraday returns and new evidence from daily returns autocorrelations can switch sign and become positive at the rebalancing horizon second the cross sectional variance in expected returns is larger when more traders rebalance this effect generates seasonality in the cross section of stock returns which can help explain available empirical evidence

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

time to cook expenditure at retirement in spain detailed panel expenditure data from spain reveal little evidence of a retirement consumption puzzle in 1985 2004 there is a drop in food at home expenditure in the later years of the sample along with evidence of households paying lower prices for the food they purchase after retirement however our findings are consistent with a model that allows for home production as long as one accounts for the greater participation in housework by men after retirement coinciding with this latter period our work adds to the evidence from several countries and helps in reconciling the retirement consumption puzzle with life cycle models

option pricing and replication with transactions costs transactions costs invalidate the black scholes arbitrage argument for option pricing since continuous revision implies infinite trading discrete revision using black scholes deltas generates errors which are correlated with the market and do not approach zero with more frequent revision when transactions costs are included this paper develops a modified option replicating strategy which depends on the size of transactions costs and the frequency of revision hedging errors are uncorrelated with the market and approach zero with more frequent revision the technique permits calculation of the transactions costs of option replication and provides bounds on option prices

how social security and medicare affect retirement behavior in a world of incomplete markets this paper provides an empirical analysis of how the u s social security and medicare insurance system affect the labor supply of older males in the presence of incomplete markets for loans annuities and health insurance we estimate a detailed dynamic programming dp model of the joint labor supply and social security acceptance decision focusing on a sample of males in the low to middle income brackets whose only pension is social security the dp model delivers a rich set of predictions about the dynamics of retirement behavior and comparisons of actual vs predicted behavior show that the dp model is able to account for wide variety of phenomena observed in the data including the pronounced peaks in the distribution of retirement ages at 62 and 65 the ages of early and normal eligibility for social security benefits respectively we identify a significant fraction of health insurance constrained individuals who have no form of retiree health insurance other than medicare and who can only obtain fairly priced private health insurance via their employer s group health plan the combination of significant individual risk aversion and a long tailed pareto distribution of health care expenditures implies that there is a significant security value for these individuals to remain employed until they are eligible for medicare coverage at age 65 overall our model suggests that a number of heretofore puzzling aspects of retirement behavior can be viewed as artifacts of particular details of the social security rules whose incentive effects are especially strong for lower income individuals and those who do not have access to fairly priced loans annuities and health insurance

portfolio choice with illiquid assets we present a model of optimal allocation to liquid and illiquid assets where illiquidity risk results from the restriction that an asset cannot be traded for intervals of uncertain duration illiquidity risk leads to increased and state dependent risk aversion and reduces the allocation to both liquid and illiquid risky assets uncertainty about the length of the illiquidity interval as opposed to a deterministic nontrading interval is a primary determinant of the cost of illiquidity we allow market liquidity to vary from normal periods when all assets are fully liquid to illiquidity crises when some assets can only be traded infrequently the possibility of a liquidity crisis leads to limited arbitrage in normal times investors are willing to forgo 2 of their wealth to hedge against illiquidity crises occurring once every 10 years this paper was accepted by itay goldstein finance

spending retirement on planet vulcan the impact of longevity risk aversion on optimal withdrawal rates corrected july 2011 recommendations from the media and financial planners regarding retirement spending rates deviate considerably from utility maximization models this study argues that wealth managers should advocate dynamic spending in proportion to survival probabilities adjusted up for exogenous pension income and down for longevity risk aversion

transaction costs and asset prices a dynamic equilibrium model in this article we study the effects of transaction costs on asset prices we assume an overlapping generations economy with a riskless liquid bond and many risky stocks carrying proportional transaction costs we obtain stock prices and turnover in closed form surprisingly a stock s price may increase in transaction costs and a more frequently traded stock may be less adversely affected by an increase in transaction costs calculations based on the marginal investor overestimate the effects of transaction costs for realistic parameter values transaction costs have very small effects on stock prices but large effects on turnover

directed attention and nonparametric learning abstract this paper examines the implications of learning for the effects of ambiguity aversion the key result is that since agents naturally choose to learn about the sources of uncertainty that reduce utility the most information acquisition attenuates the most severe effects of ambiguity aversion the specific setting we study is the canonical consumption savings problem agents endogenously learn most about income dynamics at the very lowest frequencies while ambiguity aversion typically implies in this setting excessive extrapolation of income shocks that effect is eliminated here furthermore deviations of consumption from the full information benchmark are largest at high frequencies so the model naturally generates overreaction of consumption to predictable short run income variation

efficient trading strategies in the presence of market frictions we provide a price characterization of efficient contingent claims that is chosen by at least a rational agent in multiperiod economies with market frictions frictions include market incompleteness transaction costs short selling and borrowing costs we characterize the inefficiency cost of a trading strategy its required investment minus the largest amount necessary to obtain the same utility level and we propose a measure of portfolio performance we show that arbitrage bounds cannot be tightened based on efficiency without restricting preferences or endowments we observe common investment strategies becoming inefficient with market frictions and others rationalized by them in this article we characterize efficient contingent claims to future consumption consumption bundles in multiperiod economies with uncertainty taking a wide range of market frictions into account 1 such as dynamic market

presidential address asset price dynamics with slow moving capital i describe asset price dynamics caused by the slow movement of investment capital to trading opportunities the pattern of price responses to supply or demand shocks typically involves a sharp reaction to the shock and a subsequent and more extended reversal the amplitude of the immediate price impact and the pattern of the subsequent recovery can reflect institutional impediments to immediate trade such as search costs for trading counterparties or time to raise capital by intermediaries i discuss special impediments to capital formation during the recent financial crisis that caused asset price distortions which subsided afterward after presenting examples of price reactions to supply shocks in normal market settings i offer a simple illustrative model of price dynamics associated with slow moving capital due to the presence of inattentive investors i address the implications for asset price dynamics of the apparent slow movement of investment capital to trading opportunities the arrival of new capital to an investment opportunity can be delayed by fractions of a second in some markets for example an electronic limit order book market for equities or by months in other markets such as that for catastrophe risk insurance accordingly prices respond to supply or demand shocks with a sharp reaction because of the relatively small subset of capital and thus risk bearing capacity that is immediately available to absorb a shock on short notice such a price impact is substantially reversed over time as additional capital becomes available the amplitude of the immediate price impact and the pattern of the subsequent recovery can reflect many sorts of attention costs to trade as well as institutional impediments to capital movement such as search costs for trading

a computational scheme for optimal investment consumption with proportional transaction costs abstract we consider the optimal investment consumption strategy of an investor who can invest in a stock and a bank we consider the case where proportional transaction costs are present and the objective is to maximize the discounted utility of consumption we describe an efficient computational scheme that transforms the arising free boundary problem to a sequence of fixed boundary problems we prove the convergence of the scheme and also show that the converged solution is the optimal value function finally we compare and contrast the results obtained by our procedure with certain well known results and approximations the proposed scheme also lends itself to optimizing portfolios with multiple risky assets

endogenous labor leisure investment choice under time constraints we posit the opportunity cost of time required to manage risky investments including conducting research and performance monitoring as a potential explanation for the equity premium puzzle an economic agent who should allocate a limited amount of time to labor leisure and risky investment is subject to the opportunity time cost of investment activity which is foregone labor or leisure our model envisages its impact on equity premium and volatility in the presence of such a time constraint in particular with closed form solutions to the risky asset returns volatility and risk free rate in a simple equilibrium framework wherein agents have log utility the model is shown to yield excess return and volatility consistent with historical values observed in the u s stock market even with a small amount of time cost in addition the model enables us to sort out the impact of endogenous labor leisure choice on return dynamics by comparing it with the exogenous labor income case

sluggish responses of prices and inflation to monetary shocks in an inventory model of money demand we examine the responses of prices and inflation to monetary shocks in an inventory theoretic model of money demand we show that the price level responds sluggishly to an exogenous increase in the money stock because the dynamics of households money inventories leads to a partially offsetting endogenous reduction in velocity we also show that inflation responds sluggishly to an exogenous increase in the nominal interest rate because changes in monetary policy affect the real interest rate in a quantitative example we show that this nominal sluggishness is substantial and persistent if inventories in the model are calibrated to match u s households holdings of m2

lapm a liquidity based asset pricing model the intertemporal capm predicts that an asset s price is equal to the expectation of the product of the asset s payoff and a representative consumer s intertemporal marginal rate of substitution this paper develops an alternative approach to asset pricing based on corporations desire to hoard liquidity our corporate finance approach suggests new determinants of asset prices such as the distribution of wealth within the corporate sector and between the corporate sector and the consumers also leverage ratios capital adequacy requirements and the composition of savings affect the corporate demand for liquid assets and thereby interest rates starting with the capital asset pricing model capm derived by sharpe 1964 lintner 1965 and mossin 1966 market finance has emphasized the role of consumers time preference and risk aversion in determining asset prices the intertemporal consumption based asset pricing model e g rubinstein 1976 lucas 1978 breeden 1979 harrison and kreps 1979 cox ingersoll and ross 1985 hansen and jagannathan 1991 predicts that an asset s current price is equal to the expectation conditioned on current information of the product of the asset s payoff and a representative consumer s intertemporal marginal rate of substitution imrs while fundamental this dominant paradigm for pricing assets has some wellrecognized shortcomings see below and there is clearly scope for alternative and complementary approaches this paper begins developing one such approach based on aggregate liquidity considerations 1 our starting point is that the productive and financial spheres of the economy have autonomous demands for financial assets and that their valuations for these assets are often disconnected from the representative consumer s corporate demand for financial assets is driven by the desire to hoard liquidity in order to fulfill future cash needs in contrast with the

a structural retirement model the life cycle model analyzed here constrains most work on the main job to be full time partial retirement entails a wage reduction and frequently a job change maximum likelihood estimates of utility function parameters are designed to incorporate information on the age of leaving full time work and the age of full retirement the model closely tracks retirement behavior including peaks in retirement activity at 62 and 65 the paper explores the relation of these peaks to nonlinearities in the budget constraint created by various retirement programs policy analyses based on this and on earlier models with simpler structures are compared the retirement choice is one of the more prominent manifestations of life cycle behavior the decision is the result of an interplay between an individual s preferences and a set of incentives which change in complicated ways as the individual progresses through his or her late 50 s and 60 s the purpose of this study is to formulate and estimate a structural model which incorporates in a fundamental way this interplay between lifetime preferences and incentives and to illustrate how such a model may be used to investigate retirement behavior a structural model of this type is essential for analyzing potential policy changes which can be expected to affect incentives in varying ways over a number of years in the life cycle the current study incorporates two structural features which have frequently been omitted from previous studies first the model requires that an individual who wishes to reduce work effort below full time must accept a reduced hourly wage rate in order to do so this reflects empirical evidence from micro data sets which indicates that around one third of older individuals engage in part time work at one time or another and that regardless of whether or not these older workers change jobs to obtain part time work they usually take wage cuts as compared to their previous full time work 2 the fact that an individual is willing to accept a lower wage rate in return for the opportunity to work fewer than full time hours contains important information about the preferences of the

portfolio rebalancing and asset pricing with heterogeneous inattention can households inattention to the stock market quantitatively account for the inertia in portfolio rebalancing i address this question by introducing an observation cost into a production economy with heterogeneous agents in this environment inattention changes endogenously over time and across agents i find that inattention explains the inertia in portfolio rebalancing and its heterogeneity across households inattention also rationalizes the limited stock market participation observed in the data and improves the asset pricing performance of the model finally i present a novel testable implication linking the effects of inattention on portfolio choices and asset prices to households funding liquidity

implications of rational inattention abstract a constraint that actions can depend on observations only through a communication channel with finite shannon capacity is shown to be able to play a role very similar to that of a signal extraction problem or an adjustment cost in standard control problems the resulting theory looks enough like familiar dynamic rational expectations theories to suggest that it might be useful and practical while the implications for policy are different enough to be interesting

the social security early entitlement age in a structural model of retirement and wealth abstract a structural life cycle model of retirement and wealth attributes retirement peaks at both ages 62 and 65 to social security rules and wide heterogeneity in time preferences those with high discount rates often retire at 62 they have few assets and heavily value lost benefits from working after 62 largely ignoring potential increases in later benefits declining actuarial adjustments beginning at 65 induce those with low discount rates to retire at 65 raising the social security early entitlement age to 64 induces 5 of the population to delay retiring shifting the retirement spike from 62 to 64

dynamic market participation and endogenous information aggregation abstract this paper studies information aggregation in financial markets with recurrent investor exit and entry i consider a dynamic general equilibrium model of asset trading with private information and collateral constraints investors differ in their aversion to knightian uncertainty when uncertainty is high some investors exit the market since exiting investors information is not fully revealed by prices conditional return volatility and risk premia both increase the model also implies that exit is more likely when wealth is more concentrated in the hands of less uncertainty averse investors the model thus predicts less informative prices toward the end of a long boom moreover economies with looser collateral constraints should see more volatility due to exit and partial revelation higher capital requirements potentially improve welfare by inducing more information revelation by prices