proper risk aversion on introduit et on etudie une condition comportementale significative sur les fonctions d utilite pour les richesses qui signifie qu une loterie indesirable ne peut jamais etre rendue desirable par la presence d une loterie indesirable independante

standard risk aversion this paper introduces the concept of standard risk aversion a von neumann morgenstern utility function has standard risk aversion if any risk makes a small reduction in wealth more painful in the sense of an increased reduction in expected utility also makes any undesirable independent risk more painful it is shown that given monotonicity and concavity the combination of decreasing absolute risk aversion and decreasing absolute prudence is necessary and sufficient for standard risk aversion standard risk aversion is shown to imply not only pratt and zeckhauser s proper risk aversion individually undesirable independent risks always being jointly undesirable but also that being forced to face an undesirable risk reduces the optimal investment in a risky security with and independent return similar results are established for the effect of broad class of increases in one risk on the desirability of or optimal investment in a second independent risk

competition between exchanges a research agenda this paper describes open research questions related to the competition and market structure of financial exchanges and argues that only a combination of industrial organization and finance can satisfactorily attack these questions two examples are discussed to illustrate how the combination of these two approaches can significantly enrich the analysis the network externality puzzle which refers to the question of why trading for the same security is often split across trading venues and the impact of the multi sided character of financial exchanges on pricing and profitability

intertemporal pricing and price discrimination a semiparametric hedonic analysis of the personal computer market we apply a smooth coefficient semiparametric model to a unique high frequency data set to examine the intertemporal pricing of personal computers furthermore we test whether firms charge differential component prices for their top performance personal computers and whether premium firms charge both a premium for all their computers and a premium for their top performance ones we find nonlinear effects in the pricing of personal computer components we also find that firms in general do not charge differential prices for the components of their top performance computers in addition high quality firms charge higher premia only for their most advanced products copyright 2006 john wiley sons ltd

portfolio choice and liquidity constraints we study the infinite horizon model of household portfolio choice under liquidity constraints and revisit the portfolio specialization puzzle we show why the puzzle is robust to several model variations and argue that positive correlation between earnings shocks and stock returns is unlikely to provide an empirically plausible resolution we find that relatively small fixed costs for stock market entry are sufficient to deter stockholding because for a plausible range of parameter values households can achieve desired consumption smoothing with small or zero holdings of stocks such costs could arise from informational considerations sign up fees and investor inertia

temperance in stock market participation evidence from france we explore empirically whether earnings uncertainty and borrowing constraints deter households from the stock market consistent with the predictions of theoretical studies of portfolio choice in the presence of uninsurable earnings since recent extensions highlight the importance of the correlation between earnings and financial risks here we use a self assessed proxy from the delta tns 2002 cross sectional survey to empirically assess the impact although income risk does not affect the participation decision of households reporting a negative correlation it does lower the participation of those who report a non negative sign consistent with economic theory predictions

income hedging and portfolio decisions we examine whether the decision to participate in the stock market and other related portfolio decisions are influenced by income hedging motives economic theory predicts that the market participation propensity should increase as the correlation between income growth and stock market returns decreases surprisingly empirical studies find limited support for the income hedging motive using a rich unique dutch data set and the national longitudinal survey of the youth nlsy from the united states we show that when the income return correlation is low individuals exhibit a greater propensity to participate in the market and allocate a larger proportion of their wealth to risky assets even when the income risk is high individuals exhibit a higher propensity to participate in the market when the hedging potential is high these findings suggest that income hedging is an important determinant of stock market participation and asset allocation decisions

wealth and portfolio composition theory and evidence we examine a survey of 6010 u s households and estimate a model for household portfolio allocation we extend the conventional portfolio choice model in order to capture the observed incompleteness of household portfolios we show that the empirical specification of the joint discrete and continuous choice that characterizes household portfolio behavior is a switching regressions model with endogenous switching we go on to examine the impact of taxes on portfolio composition using detailed survey data to calculate precisely the marginal tax rate facing each household finally we estimate wealth elasticities of demand for a range of assets and liabilities

how important is precautionary saving we estimate how much of the wealth of a sample of psid respondents is held because some households face more income uncertainty than others we begin by solving a theoretical model of saving which we use to develop appropriate measures of uncertainty we then regress measures of wealth on our measures of uncertainty and find evidence that households engage in precautionary saving finally we simulate the wealth distribution that our empirical results imply would prevail if all households had the same uncertainty as the lowest uncertainty group we find that between 39 and 46 percent of wealth in our sample is attributable to the extra uncertainty that some consumers face compared to the lowest uncertainty group

structural estimation of stock market participation costs abstract this paper develops and estimates a dynamic model of stock market participation where consumers decisions regarding stock market participation are influenced by participation costs the practical significance of the participation costs is considered as being a channel through which financial education programs can affect consumers investment decisions using household data from the panel study of income dynamics i estimate the magnitude of the participation cost allowing for individual heterogeneity in it the results show the average stock market participation cost is about 4 6 of labor income however it varies substantially over consumers life the model successfully predicts the level of the observed participation rate and the increasing pattern of stock market participation over the consumers life cycle

decreasing risk aversion and mean variance analysis on formule un ensemble de postulats d aversion pour le risque absolu decroissant et on montre que seules les fonctionnelles d utilite moyenne variance peuvent les satisfaire

return and dynamics the path of labor migration when workers differ in their skills and information is asymmetric an implementation of the theory of labor migration under asymmetric information shows that return migration arises from the reinstatement of informational symmetry which induces low skill workers who are no longer pooled with high skill workers to return when workers in an occupation constitute more than two skill levels say four without loss of generality the following patterns emerge migration is sequential that is it proceeds in waves each wave breaks into workers who return and workers who stay within waves the returning migrants are the low skill workers the average skill level of migrants is rising in the order of their wave excerpt

the determinants of household risky asset holdings australian evidence on background risk and other factors we study the portfolio allocation decisions of australian households using the relatively new household income and labour dynamics in australia hilda survey we focus on household allocations to risky financial assets our empirical analysis considers a range of hypothesised determinants of these allocations we find background risk factors posed by labor income uncertainty and health risk are important credit constraints and observed risk preferences play the expected role a positive age gradient is identified for risky asset holdings and home ownership is associated with greater risky asset holdings a unifying theme for many of our empirical findings is the important role played by financial awareness and knowledge in determining risky asset holdings many non stockholding households appear to lack the experience and financial literacy that might enable them to benefit from direct investment in stocks

the nature of precautionary wealth abstract this paper uses the panel study of income dynamics to provide some of the first direct evidence that wealth is systematically higher for consumers with predictably greater income uncertainty however the apparent pattern of precautionary wealth is not consistent with a standard parameterization of the life cucle model in which consumers are patient enough to begin saving for retirement early in life wealth is estimated to be far less sensitive to uncertainty than implied by that model instead our results suggest that over most of their working life time consumers behave in accordance with the buffer stock models of saving described in carroll 1992 1997 or deaton 1991 in which consumers hold wealth principally to insulate consumption against near term fluctuations in income

stockholding behavior of u s households evidence from the 1983 1989 survey of consumer finances most households persistently invest in riskless assets but not stocks and may do so because they perceive information required for market participation to be costly relative to expected benefits in a consumption capital asset pricing model ccapm increased risk aversion income risk and lower resources reduce the information expense sufficient to deter stockholding bivariate probit analysis using the 1983 1989 survey of consumer finances shows that households with lower risk aversion higher education and greater wealth who were nonstockholders in 1983 had an increased conditional probability of entering by 1989 whereas 1983 stockholders with lower resources more limited education and greater risk aversion were more likely to be nonstockholders by 1989

portfolio choice in the presence of background risk in this paper we focus on how the presence of background risks from sources such as labour and entrepreneurial income influences portfolio allocations this interaction is explored in a theoretical model that is calibrated using cross sectional data from a variety of sources the model is shown to be consistent with some but not all aspects of cross sectional observations of portfolio holdings the paper also provides a survey of the extensive theoretical and empirical literature on portfolio choice

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

would a risk averse newsvendor order less at a higher selling price we model a risk averse newsvendor s decision making behavior with some commonly used classes of utility functions within the expected utility theory eut framework under fairly general conditions of eut we show that a risk averse newsvendor will order less than an arbitrarily small quantity as selling price gets larger if price is higher than a threshold value i e the optimal order quantity decreases as the selling price increases

endogenous life cycle housing investment and portfolio allocation this paper develops a life cycle portfolio allocation model to address the effects of housing investment on the portfolio allocation of households the model employs a comprehensive housing investment structure epstein zin recursive preferences and a stock market entry cost furthermore rather than resorting to calibration we estimate the value of the relative risk aversion and elasticity of intertemporal substitution the model shows that housing investment has a strong crowding out effect on investment in risky assets throughout the life cycle we further find that the effect of the presence of housing investment on households portfolio allocation is larger than the effect of having ez recursive preferences jel classification g0 g11 g12 d10

the effects of marital status and children on savings and portfolio choice this paper investigates the impact of demographic shocks on optimal decisions about saving life insurance and most centrally asset allocation we analyze these choices within the framework of a life cycle model that features exogenous changes in family composition heterogeneity in lifetime income and uninsurable fluctuations in earnings and medical costs our analysis indicates that marital status transitions and children can have important effects on optimal household decisions widowhood induces sharp reductions in the portfolio shares in stock and the impact is largest for women and individuals with children divorce causes men and women to reallocate their portfolios in different directions men choose much riskier allocations while women opt for safer ones children play a fundamental role in the optimal portfolio decisions men with children for example increase their shares in response to divorce by less than half as much as men without children comparing our simulation results with panel data evidence on stockholding from the psid and the hrs we conclude that changes in marital status and children matter empirically as well but not always in the ways that the model predicts

the role of labor income risk in household risk taking abstract in fifteen european countries china and the us stocks and business equity as a share of total household assets are represented by an increasing and convex function of income wealth a parsimonious model fitted to the data shows why background labor income risk can explain much of this risk taking pattern uncontrollable labor income risk stresses middle income households more because labor income is a larger fraction of their total lifetime resources compared with the rich in response middle income households reduce controllable financial risk richer households having less pressure can afford more risk taking the poor take low risk because they avoid jeopardizing their subsistence consumption

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

stock market participation family responses to housing consumption commitments as of 2007 many households had taken on very substantial commitments to housing and companion mortgage payments at the same time they held little in the way of a traditional buffer stock of safer liquid assets but were more likely to have opened stock market accounts many of these families when experiencing subsequent mortgage payment difficulties are shown to have been more likely to exit the stock market mortgage difficulties also inhibited families from becoming new stock market participants in this way stocks seem to have likely experienced some direct and indirect collateral damage from the housing market 2007 9

inefficiencies in the geographical operation of labour markets curry l 1985 inefficiencies in the geographical operation of labour markets reg studies 19 203 215 after postulating an efficient overall competitive spatial price equilibrium in labour markets the real world map of wages and labour flows is introduced as an inefficient form of this configuration because of opportunities not being exploited and wages not being correct due to ignorance since these markets operate via local information and income flows the employment status of an individual affects that of his neighbours depending on the intensity of labour demand and the coupling strength between contiguous pairs on a regular lattice the economy can break up into polarized patches of different economic climates singularities now develop and previously monotonic functions develop flat parts

who benefits from an open limit order book the nyse opened the limit order book to off exchange traders during trading hours we address the welfare implications of this change in market structure we model a market similar to the auction that the exchange uses to open the trading day we consider two different environments in the first only the specialist sees the limit order book while in the second the information in the book is available to all traders we compare equilibria and find that traders who demand liquidity are better off when the book is open while liquidity suppliers are better off when the book is closed

does buffer stock saving explain the smoothness and excess sensitivity of consumption one of the lasting contributions to modernday consumer theory is the idea that consumption is determined by the expected value of lifetime resources or permanent income the modern day specification of this concept is typically presented as a special case of intertemporalchoice theory where felicity functions are quadratic labor income is stochastic there are no restrictions on borrowing consumers have infinite horizons and expectations are formed rationally we refer to this model as the permanentincome hypothesis pih although the pih has considerable intuitive appeal a series of influential papers published after its inception revealed two notable discrepancies between the model s predictions and aggregate data first the model predicts that consumption growth should be more volatile than income growth if aggregate income growth has positive serial correlation as the quarterly data suggest it does yet aggregate consumption growth is in fact much smoother than aggregate income growth angus deaton 1987 john y campbell and deaton 1989 jordi gali 1991 second the pih predicts that consumption changes should be orthogonal to predictable or lagged income changes yet the coffelation between consumption growth and lagged income growth has been found to be one of the most robust features of aggregate data for example marjorie a flavin 1981 alan s blinder and deaton 1985 campbell and n gregory mankiw 1989 orazio p attanasio and guglielmo weber 1993 thus aggregate consumption growth has been described as exhibiting two puzzles it is both excessively smooth relative to current labor income growth and excessively sensitive to lagged labor income growth 2 in response to these and other empirical anomalies researchers have recently sought out modifications of the pih framework chief ludvigson federal reserve bank of new york 33 liberty street new york ny 10045 michaelides university of cyprus p o box 20537 1678 nicosia cyprus a previous version of this paper appeared under the title can we explain the consumption excesses yet aggregate consumption implications of buffer stock saving behavior for many helpful comments we thank orazio attanasio dave backus ben bernanke john y campbell christopher carroll todd clark angus deaton pierreolivier gourinchas bo honore james kahn martin lettau costas meghir christina paxson steve pischke andrew samwick christopher sims mark watson guglielmo weber michael woodford steve zeldes and two anonymous referees conference participants at the national bureau of economic research summer workshop on the aggregate implications of microeconomic consumption behavior july 1998 the tmr workshop on saving and pensions center tilburg university march 1999 and the new york area macroeconomics workshop october 1998 seminar participants at columbia university insead the new york federal reserve university college london london business school city university business school university of cyprus tel aviv university and jeffrey brown for excellent research assistance the views expressed are those of the authors and do not necessarily reflect those of the federal reserve bank of new york or the federal reserve system any errors or omissions are the responsibility of the authors 1 note that the important insight of danny quah 1990 that individuals may be better able than econometricians to distinguish short run from long run innovations to their income cannot resolve the excess smoothness puzzle laid out in campbell and deaton 1989 these authors show that in the context of the pih excess sensitivity and excess smoothness are the same phenomena in addition campbell 1987 demonstrates that superior information of the type emphasized by quah will show up in households saving behavior and using this information allows the econometrician to control for the agent s private information when predicting income since excess sensitivity is well established and controlling for saving does not eliminate it see campbell and deaton 1989 the observed smoothness of consumption cannot be explained by superior information on the part of permanent income consumers see deaton 1992 for further discussion 2 philippe bacchetta and stefan gerlach 1997 and ludvigson 1999 document another kind of excess sensitivity the correlation between consumption growth and predictable changes in consumer credit although we do not explore these findings here ludvigson finds that a bufferstock model with time varying liquidity constraints can replicate such a correlation

time horizon and the discount rate abstract we consider an economy a la lucas 1978 econometrica46 1429 1446 with a risk averse representative agent the exogenous growth rate of the economy follows a random walk we characterize the set of utility functions for which it is efficient to discount more distant cash flows at a lower rate the benchmark result is that when the growth rate is almost surely nonnegative the yield curve is decreasing if and only if relative risk aversion is decreasing with wealth relaxing the assumption on the absence of recession requires more restrictions on preferences such as increasing relative prudence journal of economic literature classification numbers d81 d91 q25 q28

borrowing costs and the demand for equity over the life cycle abstract we construct a life cycle model that delivers realistic behavior for both equity holdings and borrowing the key model ingredient is a wedge between the cost of borrowing and the risk free investment return borrowing can either raise or lower equity demand depending on the cost of borrowing a borrowing rate equal to the expected return on equity which we show roughly matches the data minimizes the demand for equity alternative models with no borrowing or limited borrowing at the risk free rate cannot simultaneously fit empirical evidence on borrowing and equity holdings

a news utility theory for inattention and delegation in portfolio choice recent evidence suggests that investors are inattentive to their portfolios and hire expensive portfolio managers this paper develops a life cycle portfolio choice model in which the investor experiences loss averse utility over news and can ignore his portfolio in such a model the investor prefers to ignore and not rebalance his portfolio most of the time because he dislikes bad news more than he likes good news such that expected news causes a first order decrease in utility consequently the investor has a first order willingness to pay a portfolio manager who rebalances actively on his behalf moreover the investor can diversify over time and his consumption aligns with predictions of mental accounting i structurally estimate the preference parameters by matching stock shares and stock market non participation over the life cycle my parameter estimates are in line with the literature generate reasonable intervals of inattention and simultaneously explain consumption and wealth accumulation over the life cycle here it matters that news utility preserves first order risk aversion even in the presence of stochastic labor income which also causes stock shares to rise in wealth

life cycle portfolio choice the role of heterogeneous under diversification the empirical work on household portfolio choice documents two facts one the stock market participation rate is low and hump shaped over the life cycle two the conditional share of stocks is also low but does not appear to change much during the life cycle in contrast the standard life cycle portfolio choice model predicts high and monotonically increasing participation rates and conditional stock shares that are low and exhibit dramatic changes with age in this paper i consider a number of extensions to this basic framework i find that a small per period participation cost is needed to generate a hump shaped life cycle profile of participation rates under a realistic calibration the quantitative effect is minor progressive social security and the assumption that the risk of stock portfolios is declining in household wealth as a consequence of better diversification opportunities an assumption that has some empirical support though provide substantial amplification and significantly improve the ability of the model to match the data under diversification also reduces the average portfolio share of stocks conditional on participation and together with the intergenerational transmission of wealth makes it insensitive to age consistent with the empirical evidence

life cycle saving insights from the perspective of bounded rationality this paper provides a new life cycle model that takes into account key elements of bounded rationality the paper shows that the model can account for patterns in the data that are hard to explain by the standard life cycle model among other patterns the model predicts that typically the young either hold no equity or their equity portfolio share is rather low and then increases over working life the analytical solution of the model demonstrates its high degree of tractability

tournaments with gaps a standard tournament contract specifies only tournament prizes if agents performance is measured on a cardinal scale the principal can complement the tournament contract by a gap which defines the minimum distance by which the best performing agent must beat the second best to receive the winner prize we analyze a tournament with two risk averse agents under unlimited liability the principal strictly benefits from a gap by partially insuring the agents and thereby reducing labor costs if the agents are protected by limited liability the principal sticks to the standard tournament

compensating wage differentials for schooling risk in denmark in this paper we analyse the association between wage differentials and risk using detailed information on length and type of education as seen in danish administrative registers our contribution to the literature is that we distinguish between transitory time series and permanent cross sectional income shocks and estimate the compensation for both sorts of risk we find that wage risk in a given education cell is associated with higher wages while skewness is associated with lower wages as a robustness check we see that ad hoc risk measures based on earnings mobility indicators confirm these findings

robustly strategic consumption portfolio rules with informational frictions this paper provides a tractable continuous time constant absolute risk aversion gaussian framework to explore how the interactions of fundamental uncertainty model uncertainty due to a preference for robustness and state uncertainty due to information processing constraints rational inattention affect strategic consumption portfolio rules and precautionary savings in the presence of uninsurable labor income specifically after solving the model explicitly i compute and compare the elasticities of strategic asset allocation and precautionary savings to risk aversion robustness and inattention furthermore for plausibly estimated and calibrated model parameters i quantitatively analyze how the interactions of model uncertainty and state uncertainty affect the optimal share invested in the risky asset and show that they can provide a potential explanation for the observed stockholding behavior of households with different education and income levels this paper was accepted by neng wang finance

portfolio selection with mental accounts and background risk abstract das et al 2010 develop a model where an investor divides his or her wealth among mental accounts with motives such as retirement and bequest nevertheless the investor ends up selecting portfolios within mental accounts and an aggregate portfolio that lie on the mean variance frontier importantly they assume that the investor only faces portfolio risk in practice however many individuals also face background risk accordingly our paper expands upon theirs by considering the case where the investor faces background risk our contribution is threefold first we provide an analytical characterization of the existence and composition of the optimal portfolios within accounts and the aggregate portfolio second we show that these portfolios lie away from the mean variance frontier under fairly general conditions third we find that the composition and location of such portfolios can differ notably from those of portfolios on the mean variance frontier

portfolio inertia and stock market fluctuations this paper uses population wide data from the panel study of income dynamics and the survey of consumer finances to resolve the conflict between overtrading and inactivity shown in administrative data on brokerage and retirement accounts respectively considerable inertia is found and linked to characteristics e g limited education or resources but less to index movements the downswing has encouraged staying out rather than getting out of the market the small minority with brokerage accounts exhibits important differences in trading patterns relative to the population and invests small fractions of wealth in brokerage accounts results strengthen the case for default options in retirement accounts and built in trading provisions in mutual funds

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

optimal financial knowledge and wealth inequality we show that financial knowledge is a key determinant of wealth inequality in a stochastic life cycle model with endogenous financial knowledge accumulation where financial knowledge enables individuals to better allocate lifetime resources in a world of uncertainty and imperfect insurance moreover because of how the us social insurance system works better educated individuals have most to gain from investing in financial knowledge our parsimonious specification generates substantial wealth inequality relative to a one asset saving model and one in which returns on wealth depend on portfolio composition alone we estimate that 30 40 percent of retirement wealth inequality is accounted for by financial knowledge

mental accounting access motives and overinsurance people exercising mental accounting have an additional motive for buying insurance they perceive a risk of having insu cient funds available to self insure in this way insurance protects the consumption value of the insured asset beyond the expenditure to acquire replace it this complements previous approaches based on probability weighting and loss aversion to explain the high pro tability of warranties and an aversion toward deductibles it helps to account for why the value of a warranty is found to be positively related to the value of the product and why there is seemingly contradictory empirical evidence on how household income a ects demand for warranties the adapted model rationalizes a strong aversion to deductibles and explains the observed sensitivity of this aversion to the insurance context finally it predicts a strong impact of how an insurer pays out bene ts on the value and cost of insurance this can explain both the evidence on strong deductible aversion for ood insurance and the lack of such evidence for long term care insurance jel classi cation d11 d14 d81 g22

heterogeneous background risks and portfolio choice evidence from micro level data we construct a set of household level background risk variables to capture the covariance structure of three nonfinancial assets and two financial assets these risks are in general statistically significant and economically important for a household s stock market participation and stockholdings a one standard deviation increase in background risks reduces the participation probability by 11 and the stockholdings to wealth ratio by 4 the volatilities of labor income housing value and business income reduce a household s participation and stockholdings a household with labor income highly correlated with stock bond returns is less more likely to invest in stock

risk aversion wealth and background risk we use household survey data to construct a direct measure of absolute risk aversion based on the maximum price a consumer is willing to pay for a risky security we relate this measure to consumer s endowments and attributes and to measures of background risk and liquidity constraints we find that risk aversion is a decreasing function of the endowment thus rejecting cara preferences we estimate the elasticity of risk aversion to consumption at about 0 7 below the unitary value predicted by crra utility we also find that households attributes are of little help in predicting their degree of risk aversion which is characterized by massive unexplained heterogeneity we show that the consumer s environment affects risk aversion individuals who are more likely to face income uncertainty or to become liquidity constrained exhibit a higher degree of absolute risk aversion consistent with recent theories of attitudes toward risk in the presence of uninsurable risks jel d1 d8

health and portfolio choices a diffidence approach the effect of health status on portfolio decisions has been extensively studied from an empirical viewpoint in this paper we propose a theoretical model of individuals choice of financial assets under bivariate utility functions depending on wealth and health our approach makes an extensive use of the diffidence theorem we establish the conditions under which the share of wealth held in risky assets falls as 1 individuals health status deteriorates and 2 individuals health status becomes risky these conditions are shown to be related to the behavior of the intensities of correlation aversion and of cross prudence as wealth increases

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

individual income incomplete information and aggregate consumption individual income is much more variable than aggregate per capita income i argue that aggregate information is therefore not very important for individual consumption decisions and study models of life cycle consumption in which individuals react optimally to their own income process but have incomplete or no information on economy wide variables since individual income is less persistent than aggregate income consumers will react too little to aggregate income variation aggregate consumption will be excessively smooth since aggregate information is slowly incorporated into consumption aggregate consumption will be autocorrelated and correlated with lagged income on the other hand the model has the same prediction for micro data as the standard permanent income model the second part of the paper provides empirical evidence on individual and aggregate income processes different models for individual income are fit to quarterly data from the survey of income and program participation making various adjustments for measurement error calibrating the consumption model using the estimated parameters for the income process yields predictions which qualitatively correspond to the empirical findings for aggregate consumption but do not match them well in magnitude

mean variance vulnerability this paper transfers the concept of gollier and pratt s gollier c j w pratt 1996 risk vulnerability and the tempering effect of background risk econometrica64 1109 1123 risk vulnerability into mean variance preferences risk vulnerability is shown to be equivalent to the slope of the mean variance indifference curve being decreasing in mean and increasing in variance next we introduce the notion of mean variance vulnerability to link the concepts of decreasing absolute risk aversion risk vulnerability properness and standardness all of the abovementioned concepts are characterized in terms of mean variance indifference curve properties and in terms of absolute risk measures

why do so few hold stocks the authors investigate why 75 percent of u s households do not hold stocks despite the equity premium and predictions of expected utility models the question is relevant for privatization asset pricing and tax progressivity issues they show that risk aversion per se heterogeneity of beliefs habit persistence time nonseparability and quantity constraints on borrowing do not account for the phenomenon a wedge between borrowing and lending rates and minimum investment requirements are plausible but empirically weak factors more promising explanations are inertia and departures from expected utility maximization there is also qualified support for nondiversifiable income risk as a contributing factor copyright 1995 by royal economic society

asset pricing with limited risk sharing and heterogeneous agents we develop a model with incomplete markets and heterogeneous agents that generates a large equity premium while simultaneously matching stock market participation and individual asset holdings the high risk premium is driven by incomplete risk sharing among stockholders which results from the combination of aggregate uncertainty borrowing constraints and a realistically calibrated life cycle earnings profile subject to idiosyncratic shocks we show that it is challenging to simultaneously match asset pricing moments and individual portfolio decisions while limited participation has a negligible impact on the risk premium contrary to the results of models where it is imposed exogenously

the impact of the new wave of financial regulation for european energy markets abstract as the financial and physical markets for energy have increasingly become intertwined energy trade is also covered by financial legislation the european commission wishes to strengthen this financial regulation of energy trade it has put forward a set of regulatory proposals aimed at stabilizing financial markets and limiting volatility of energy prices the most noteworthy are emir mad remit and the revised mifid key elements are transparency new trading venues central clearing obligations and mandatory transaction reporting this article evaluates the likely outcomes for energy markets given the new incentives for market parties it argues that although there is no ground to exempt particular energy market participants such as energy companies from financial legislation increased regulation will not necessarily bring about the effects the commission desires the causal link between derivatives trading and volatility of energy prices is not known precisely and many of the economic effects of the proposed legislation are theoretically and empirically ambiguous moreover potentially conflicting instruments and objectives risk policy inconsistency

an elementary simulation model of the job matching process within an interregional setting amrhein c g and mackinnon r d 1985 an elementary simulation model of the job matching process within an interregional setting reg studies 19 193 202 a dynamic model of a multiregional job search and migration process is developed heterogeneous skills of workers and skill requirements of employers give rise to a process that matches workers of different types to various job opportunities an optimal intraregional matching requires workers to engage in an interregional search for better opportunities in this matching process welfare levels and regional wage scales are determined welfare differentials perceived by the workers give rise to stress migration occurs if the experienced level of stress is greater than the perceived risk the behaviour of the model is examined by means of some numerical simulations and sensitivity analyses

investment flexibility and the acceptance of risk abstract the hypothesis examined in this paper is that the greater the investor s flexibility the easier it is for him to change his portfolio depending on his results the more willing he will be to accept risks when the investor has no control on the size of the risky investment but can choose between one risky and one riskless asset this conjecture is shown to be correct however if there is more than one risky asset each period counterexamples demonstrate that flexibility rarely ensures greater risk taking for the standard portfolio problem in which investors are free to determine the size of their investment in a risky asset flexibility always raises the demand for the risky asset if constant relative risk aversion is less than unity but counterexamples can always be found when the constant relative risk aversion is larger than unity journal of economic literatureclassification numbers g11 d81 d84

income risk and portfolio choice an empirical study this paper investigates the relationship between portfolio choice and labor income risk in the national longitudinal survey of youth 1979 cohort permanent income risk variability of shocks to income that have permanent effect significantly reduces the share of risky assets in the household s portfolio while transitory income risk variability of shocks with no lasting effect does not this result provides strong evidence that households portfolio choices respond to labor income risks in a manner consistent with economic theory theoretical work has shown that uninsurable labor income risk is likely to reduce the share of risky assets in an investor s portfolio pratt and zeckhauser 1987 kimball 1993 bertaut and haliassos 1997 koo 1998 1999 elmendorf and kimball 2000 in a dynamic context when labor in come consists of components of different persistence the magnitude of this effect should depend on the persistence associated with the risk the risk to a persistent component should have a larger effect than the risk to a transi tory component surprisingly however empirical work has not examined this interesting implication of the theory this paper uses the rich information con tained in the national longitudinal survey of youth 1979 cohort nlsy79 to examine this implication we assume that labor income has two components permanent and transitory we then measure the risks of the components for a sample of households in the survey and estimate their effects on the risky asset share previous empirical

some stronger measures of risk aversion in the small and the large with applications the arrow pratt measures of risk aversion for von neumann morgenstern utility functions have become workhorses for analyzing problems in the microeconomics of uncertainty they have been used to characterize the qualitative properties of demand in insurance and asset markets to examine the properties of risk taking in taxation models and to study the interaction between risk and life cycle savings problems to name just a few applications equally importantly they have generated the linear risk tolerance class of utility functions which has provided canonical examples in such diverse areas as portfolio theory and the theory of teams despite these successes there have been a number of areas for which the results have been weaker than hoped it is natural to use the risk aversion measures to compare the behavior of individuals in risky choice situations for example consider the individual portfolio choice problem in a two asset world with a riskless asset and a risky asset if individual a has a uniformly higher arrow pratt coefficient of risk aversion than individual b then b will always choose a portfolio combination with more wealth invested in the risky asset but suppose that both assets are risky now there is no obvious sense in which the more risk averse individual can be said to hold a less risky portfolio but it seems strange that such a simple alteration should destroy the analytics which support the basic intuition similarly consider the basic insurance problem if one individual a is more risk averse than another b in the arrow pratt sense it follows that a will pay a larger premium to insure against a random loss than will b typically though an individual evaluates partial rather than total insurance that is only some gambles can be insured against and others must be retained in this case even when the gambles which are retained are independent from those which are insured it is no longer true that the individual whose arrow pratt measure of risk aversion is higher will pay a larger insurance premium the situation is no better when we consider comparative statics exercises for a single individual decreasing absolute risk aversion in the sense of arrow and

international portfolio choice liquidity constraints and the home equity bias puzzle this paper solves for optimal international portfolio choice in the presence of liquidity constraints and undiversifiable labor income risk optimal portfolios are internationally diversified while positive correlation between domestic stock market returns and permanent labor income shocks can generate a complete portfolio specialization in foreign stocks nevertheless either small costs associated with investing abroad or a slightly positive domestic to foreign equity premium differential are sufficient to either deter households from participating in a foreign market or generate a substantial bias for home equities the benefits of international diversification are limited because consumption fluctuations can be smoothed with a small amount of buffer stock saving while exchange rate risk makes foreign investments less appealing to risk averse investors

testing for prudence and skewness seeking numerous theoretical predictions such as precautionary saving or preventive behavior have been derived for prudent decision makers further prudence can be characterized as downside risk aversion and plays a key role in preference for skewness we use a simple experimental method to test for prudence and skewness preference in the laboratory and compare the two to this end we introduce a novel graphical representation of compound lotteries that is easily accessible to subjects and test it for robustness using a factorial design prudence is observed on the aggregate and individual level we find that prudence does not boil down to skewness seeking we further provide some theoretical explanations for this result this paper was accepted by peter wakker decision analysis

hedging familiarity and portfolio choice we exploit the restrictions of intertemporal portfolio choice in the presence of non nancial income risk to design and implement tests of hedging that use the information contained in the actual portfolio of the investor we use a unique dataset of swedish investors with information broken down at the investor level and into various components of wealth investor income tax positions and investor demographic characteristics portfolio holdings are identi ed at the stock level we show that investors do not engage in hedging but invest in stocks closely related to their non nancial income we explain this with familiarity that is the tendency to concentrate holdings in stocks with which the investor is familiar in terms of geographical or professional proximity or that he has held for a long period we show that familiarity is not a behavioral bias but is information driven familiarity based investment allows investors to earn higher returns than they would have otherwise earned if they had hedged

asset market participation and portfolio choice over the life cycle using error free data on life cycle portfolio allocations of a large sample of norwegian households we document a double adjustment as households age a rebalancing of the portfolio composition away from stocks as they approach retirement and stock market exit after retirement when structurally estimating an extended life cycle model the parameter combination that best fits the data is one with a relatively large risk aversion a small per period participation cost and a yearly probability of a large stock market loss in line with the frequency of stock market crashes in norway

precautionary portfolio behavior from a life cycle perspective abstract the literature on household asset accumulation draws a sharp distinction between short run precautionary motives to buffer consumption from annual income shocks and long run life cycle considerations under income certainty however estimates of shock persistence imply considerable career uncertainty we study long run precautionary motives for life cycle wealth accumulation and portfolios allowing for uncertain returns incomes and lifespan we separate the effects of various factors on mean and median asset holdings including education risk aversion household heterogeneity bequests impatience variance and serial correlation of income shocks numerical solutions are compared with data from the 1992 survey of consumer finances

asset holding and consumption volatility we investigate the possibility that limited participation in asset markets and the stock market in particular might explain the lack of correspondence between the sample moments of the intertemporal marginal rate of substitution and asset returns in u k data we estimate ownership probabilities to separate likely shareholders from nonshareholders enabling us to control for changing composition effects as well as selection into the group we then construct estimates of the imrs for each of these different groups and consider their time series properties we find that the consumption growth of shareholders is more volatile than that of nonshareholders and more highly correlated with excess returns to shares in particular one cannot reject the predictions of the consumption capital asset pricing model for the group of households predicted to own both assets this is in contrast to the failure of the model when estimated on data for all households

the introduction of the euro and its effects on portfolio decisions abstract examining investment behavior related to the euro introduction we address the relevance of different investment determinants with the advent of the currency union two potential sources of portfolio reallocation can be distinguished first the diminishment of exchange rate risk and transaction costs within the emu second the increase of correlation of emu returns so that diversification benefits decreased we test for structural breaks in the holdings of german investors and estimate a market model to account for the two effects a significant decrease in national and an increase in emu and rest of the world investments can be observed comparing the observed holdings with benchmark portfolios we find that investment home bias has diminished since the euro introduction

a small world methodology of analysis of interchange energy networks the european behaviour in the economical crisis abstract european energy policy pursues the objective of a sustainable competitive and reliable supply of energy in 2007 the european commission adopted a proper energy policy for europe supported by several documents and included an action plan to meet the major energy challenges europe has to face a farsighted diversified yearly mix of energies was suggested to countries aiming at increasing security of supply and efficiency but a wide and systemic view of energy interchanges between states was missing in this paper a small world methodology of analysis of interchange energy networks iens is presented with the aim of providing a useful tool for planning sustainable energy policies a proof case is presented to validate the methodology by considering the european ien behaviour in the period of economical crisis this network is approached as a small world net from a modelling point of view by supposing that connections between states are characterised by a probability value depending on economic political relations between countries

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

smoothing with liquid and illiquid assets abstract a quantitative examination of the demand for liquid assets arising from consumption smoothing motives reveals that such demand is very low consumers faced with income streams calibrated to match income and unemployment data and returns and transactions costs calibrated to match us treasury bill data almost exclusively buy and hold illiquid long term assets even though the return premium on long term assets is quite small this is because with standard preferences savings are highly persistent even when risky income is not in the calibrated model the first order autocorrelation of savings is an order of magnitude larger than that of income

precautionary saving in the small and in the large the theory of precautionary saving is shown to be isomorphic to the arrow pratt theory of risk aversion making possible the application of a large body of knowledge about risk aversion to precautionary saving and more generally to the theory of optimal choice under risk in particular a measure of the strength of the precautionary saving motive analogous to the arrow pratt measure of risk aversion is used to establish a number of new propositions about precautionary saving and to give a new interpretation of the dreze modigliani substitution effect copyright 1990 by the econometric society

risky choices and correlated background risk the analysis of a risky project should take into account not only uncertainties about the return from that project project risk but also uncertainties associated with other ongoing projects and with exogenous factors that can impact final wealth background risk the presence of background risk can change the optimal course of action with respect to a project and ignoring such risk might lead to a poor decision most work on background risk assumes that project risk and background risk are independent and are additive in their impact on wealth however independence is often unrealistic and background risk operates in a multiplicative manner in many situations we relax the independence assumption and consider a model with both additive and multiplicative background risk the optimal decisions in the correlated setting can be very different than those that would appear optimal if the correlation were ignored the impact of correlation differs in the additive and multiplicative cases with positive correlation being beneficial in some cases and negative correlation in others the analytical and numerical results indicate that in analyzing decision making problems it is very important to understand the direction and degree of dependence between project risk and background risks