many instruments and or regressors a friendly guide this paper surveys the state of the art in the econometrics of regression models with many instruments or many regressors based on alternative namely dimension asymptotics we list critical results of dimension asymptotics that lead to better approximations of properties of familiar and alternative estimators and tests when the instruments and or regressors are numerous then we consider the problem of estimation and inference in the basic linear instrumental variables regression setup with many strong instruments we describe the failures of conventional estimation and inference as well as alternative tools that restore consistency and validity we then add various other features to the basic model such as heteroskedasticity instrument weakness etc in each case providing a review of the existing tools for proper estimation and inference subsequently we consider a related but different problem of estimation and testing in a linear mean regression with many regressors we also describe various extensions and connections to other settings such as panel data models spatial models time series models and so on finally we provide practical guidance regarding which tools are most suitable to use in various situations when many instruments and or regressors turn out to be an issue

willingness to pay for stochastic improvements of future risk under different risk aversion abstract within a general intertemporal decision making framework this work shows one individual with more k th degree k 2 n ross risk aversion always chooses more current paying to improve his future payoff distribution when such stochastic improvement satisfies the n th degree mean preserving stochastic dominance moreover when stochastic improvement of the future payoff distribution is not mean preserving the notions of linearly quadratically restricted more ross risk aversion proposed by eeckhoudt liu and meyer 2017 can help provide a clear cut comparative statics analysis

unemployment risk and precautionary wealth evidence from households balance sheets this paper examines precautionary behavior by relating job loss risk to household net worth we use existing best practice and some new strategies to deal with some problematic issues inherent in this literature regarding proxying uncertainty instrumentation and incorporating theoretical restrictions we do not find precautionary variation in the wealth holdings of households with low permanent income but do find precautionary effects for moderate and higher income households when the dependent variable is total net worth these findings are robust to several alternative specifications but we do not find precautionary responses in subaggregates of wealth that exclude home equity

precautionary saving and endogenous labor supply with and without intertemporal expected utility we analyze precautionary saving behavior in a framework with labor and nonlabor income risks an endogenous supply of labor and a representation of preferences that disentangles attitudes towards risk attitudes towards intertemporal substitution and ordinal preferences for consumption and leisure this preference structure allows us to disentangle and to describe in an intuitive way the different forces that determine precautionary saving in the small and in the large

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

the estimation of wage gains and welfare gains in self selection models the authors modify the basic self sele ction model for the effects ofeducation training unions and other activities on wages by including heterogeneity of rewards to the activity i e diffe rences across individuals in the rate of return to the activity the authors sho w that such heterogeneity creates a new form of selectionbias they provide tes ts for its presence and draw out its implications for the wage and welfare gains to the activity an empirical application provides strong support for such hete rogeneityin one particular training program copyright 1987 by mit press

optimal self protection in two periods on the role of endogenous saving self protection is a costly investment to reduce the probability of loss this paper studies optimal self protection in a two period model with endogenous saving in a setting with a binary loss we show that prudence is negatively associated with the optimal level of self protection consistent with results obtained in single period models we provide intuition for this finding with the help of a recent approach based on stochastic dominance furthermore we determine the effect of interest rate risk on optimal self protection and study a model in which a decision maker engages in advance effort to increase the probability of facing a better risky situation all our results suggest that the understanding of advance self protection crucially hinges on whether the decision maker also uses saving to optimize intertemporal consumption utility if so the fact that self protection expenditures are upfront turns out to be irrelevant

survey measures of risk aversion and prudence this paper utilizes a thought experiment conducted by the bank of italy to estimate absolute and relative risk aversion along with absolute and relative prudence for a broad cross section of italian households upper and lower bounds are calculated for each parameter and comparisons are made across socio demographic groups evidence is found of decreasing absolute risk aversion decreasing absolute prudence increasing relative risk aversion and increasing relative prudence

risk averters that love risk marginal risk aversion in comparison to a reference gamble we propose an analytical distinction between standard risk aversion based on the valuation of a single gamble and marginal risk aversion based on the change in valuation between two gambles we measure marginal risk aversion in two dimensions mean and variance data from a field experiment is used to study marginal risk aversion our results suggest that individuals rely on a reference gamble when assessing marginal risk individual responses to marginal changes in mean and variance are nearly identical in direction and magnitude suggesting that information on both standard and marginal risk aversion is needed to accurately model behavior copyright 2008 oxford university press

nontraded assets and the capm abstract asset pricing models that rely on the presence of non tradable assets such as human wealth to solve the equity premium puzzle have to confront the effect of decreasing absolute risk aversion rich investors who according to micro data hold the stock market and whose behavior is the one that matters at the margin for the determination of equilibrium asset prices are less risk averse ceteris paribus than the average consumer this paper highlights a channel through which the effect of decreasing absolute risk aversion can be overcome the existence of a positive correlation between the rates of return on traded assets and on the human capital of marginal investors

risk and precautionary saving in two person households the existing literature on precautionary saving is based almost entirely on the assumption that the household acts as if it consisted of a single individual decision taker in reality saving decisions are typically taken by two person households this paper examines the implications of this observation for the existence of precautionary saving and shows that the assumption that the individual utility functions satisfy the conditions for precautionary saving to exist can imply that the household exhibits precautionary saving but only under strong assumptions on the type of risk change being considered

an analytical approximate solution to the problem of precautionary savings abstract this paper considers the problem of precautionary savings for an expected utility specification with finite horizon the exact solution is known for only a few cases numerical methods have limited applications because of bellman s curse of dimensionality this paper derives a simple analytical approximate solution for a general specification of the felicity function which is linear in the variance of the innovations on human wealth numerically the approximation is very accurate for realistic values of the parameters of the problem

behavioral responses to risk in rural china does risk perpetuate poverty in a credit constrained economy jalan and ravallion study portfolio and other behavioral responses to measured risk using household panel data for rural china one quarter of wealth is held in unproductive liquid forms but only a small share of this appears to be a precaution against income risk the authors estimate that eliminating income risk would reduce the share of wealth held in liquid form by less than 1 percentage point moreover that effect is confined largely to middle income groups high income households do not it seems need to hold unproductive cautionary wealth and the poor probably cannot afford to do so the authors find no evidence that income risk discourages schooling but risk does inhibit the out migration of labor generally the results provide only limited support for the idea that uninsured risks promote unproductive portfolio behavior in this setting there is such an effect but it is small in magnitude and cannot be deemed an important cause of poverty

the determinants of private saving in india abstract this paper examines the determinants of private saving in the process of economic development in the light of the indian experience it is found that the saving rate rises with both the level and the rate of growth of disposable income the real interest rate on bank deposits has a significant positive impact but the magnitude of the impact is modest public saving seems to crowd out private saving but less than proportionately furthermore the spread of banking facilities in the economy and the inflation rate have a positive impact and changes in the external terms of trade a negative impact on private saving

investments in human capital wage uncertainty and public policy abstract the importance of risk characteristics of human capital for the design of tax and education policy is explored wages are uncertain and education while increasing the expected wage may increase or decrease wage variance the government has strong reasons to encourage human capital formation in the latter case partly due to the insurance effect of human capital and partly due to the way the individuals under a plausible restriction on prudence respond to changes in risk the analysis is illustrated using two models of education one where education helps the individuals make better occupational choices and a standard risk augmented becker type model

precautionary savings a panel study theoretical literature shows that income uncertainty boosts saving yet empirical work is incomplete i test for the precautionary motive for saving using panel data knowing this motive s size is important for gauging the responsiveness of saving to government programs that reduce uncertainty and for comparison to other motives such as bequests most empirical studies of precautionary saving use either aggregate time series or cross sectional data which cannot capture the effects of individual income uncertainty i derive measures of total permanent and transitory income uncertainty from panel data the national longitudinal survey and find a strong precautionary motive a doubling of uncertainty increases the ratio of wealth to permanent income by 29

skewness preference risk aversion and the precedence relations on stochastic changes this paper provides a general choice theoretic characterization of the trade off between risk and skewness whose importance in understanding risk taking behavior is well documented in empirical studies the condition under which the prudence measure kimball 1990 characterizes the strength of an individual s downside risk aversion against his own risk aversion is identified and interpreted in a unifying framework based on the concept of one stochastic dominant change preceding another and that of the desirability of a stochastic change the framework is also shown to be useful for a better understanding of the arrow pratt measure the stronger ross measure and the coincidence of the characterizations of downside risk aversion and prudence as well as the relationship between stochastic dominances of different degrees

aggregation in area yield crop insurance the linear additive model previous analyses of area yield crop insurance have used a linear additive model lam to express the relationship between individual and area yield however the theoretical foundations of the lam are unknown this shortcoming is addressed by establishing two conditions linking microvariables and lam parameters the conditions relate to the interaction of risks in individual technologies and the extent of aggregation if systemic and individual risks are additive in individual yields and if the law of large numbers hold then the lam obtains this article also shows how departures from these conditions affect the results derived from a lam analysis a classic issue in agricultural economics is the design of schemes that would offer insurance against risks in agriculture the experience with conventional crop insurance has been disappointing as insurers have struggled to obtain reliable actuarial data on individual yields skees black and barnett the primary attraction of area yield insurance schemes is that insurers do not have to contend with the informational problems of moral hazard and adverse selection halcrow these problems can be dismissed because indemnities and premiums are based not on a producer s individual yield but rather on the aggregate yield of a surrounding geographical area however the key question is how adequate are aggregate yield instruments for reducing the risks faced by producers to address this question previous studies have expressed individual yields as a linear stochastic function of area yield mahul miranda vercammen the approach has been to use the form of a linear regression model where the dependent variable is the yield of an individual producer the only independent variable is area yield and the additive random error term measures omitted individual specific factors uncorrelated with area yield thus the model decomposes variations in individual yield in to variations in area yield that represent systemic risk and bharat ramaswami is senior economist in the indian statistical

effects of budgetary constraints on international tourism expenditures abstract this paper implements a logistic transition regression model to examine the relationships between gdp per capita and international tourism expenditures across countries in 2001 2010 by types of savings regimes while studies have focused on the effect of income on international tourism expenditures none consider the nonlinear smooth transition status of savings and its impacts on discretionary spending and hence expenditure on tourism the impact of income on tourism expenditures can vary under different savings regimes the results show that in a low savings regime the effect of an increase in the gdp per capita on international tourism expenditures is more pronounced in a high savings regime there is strong motivation for precautionary savings and tourism is considered a luxury therefore such spending is crowded out by an increase in savings as gdp per capita increases although international tourism expenditures also increase with gdp per capita they do so at a slower rate these findings establish an accurate understanding of the effects of savings on international tourism expenditures

cross hedging under multiplicative basis risk cross hedging price risk in an incomplete financial market creates basis risk we propose a new way of modeling basis risk where price risk and basis risk are combined in a multiplicative way under this specification positive prudence is a necessary and sufficient condition for underhedging in an unbiased market using the example of cross hedging jet fuel price risk with crude oil futures we show that the new specification is superior in describing the price series and that optimal cross hedges differ significantly from those derived under the traditional additive cross hedging model

measuring customer relationships the case of the retail banking industry arguing that gaap is ill suited for estimating the future profitability of intangibles the accounting literature e g kaplan and norton 1996 lev 2001 has recently proposed alternative measurement models these models view intangibles as composed of a set of fundamental business activities and use multiple financial and nonfinancial metrics causally interlinked to profits to represent this view using a unique and proprietary cross sectional data set of the retail banking industry we provide some of the first tests on the empirical validity of such measurement models we characterize the core deposit intangible an important retail banking intangible representing a bank s relationships with its customers using financial and nonfinancial metrics on price service customer usage and customer satisfaction we find that the metrics do not individually predict future earnings but gain individual significance in a collective setting increasing the predictive power substantially we argue that this result occurs because the activities underlying the measures are causally interlinked to profits and explicitly illustrate these linkages with a structural path model our measurement model also predicts significant interactive effects in the way our measures are informative about future profits and we document such effects not just among the individual measures but also across the measures and environmental factors such as the bank s strategy in sum our measurement model illustrates the key drivers measures and interactions in retail banking customer relationships

precaution and liquidity in the demand for housing we exploit cross sectional mortgage data to investigate the importance of liquidity constraints and a precautionary motive in the demand for housing households that are not liquidity constrained consume housing services essentially as the life cycle hypothesis suggests but with a significant precautionary component households that are liquidity constrained in terms of not meeting standard loan to value or payments to income constraints are similar to unconstrained households in most respects including the precautionary motive but they respond somewhat less to fluctuations in their lifetime income suggesting some influence of bank induced liquidity constraints we additionally find however that banks enforce liquidity constraints only weakly jel d91 d12 r21 i introduction the benchmark theory in the economics of consumption is the life cycle or permanent income hypothesis lcpi based on the work of modigliani and brumberg 1954 and friedman 1957 its empirical validity is sometimes questionable especially when compared against alternatives that incorporate liquidity constraints or the precautionary motive for saving see for instance deaton 1992 for a survey rejection of the lcpi may however be just a manifestation of the poor quality of consumption data at the micro level these data are typically subject to the reporting biases and omissions inherent in consumer surveys there are further difficulties in measuring a desired stream of consumption services nondurable consumption goods are a small fraction of total consumption and in the case of food essentials hardly a consumer choice variable durable consumption goods have the feature that they are lumpy and that the consumption services at any point in time are hard to measure we propose to test the lcpi at the micro level with a quite different type of data the data are obtained from the residential mortgage finance database collected by the national association of realtors they are based on actual home purchases and the associated mortgage transactions reported by realtors and thus avoid some of the reporting biases of the consumer surveys more important they allow us to accurately identify households that in principle have instantaneous access to additional liquidity by lowering the down payment for the house purchase or increasing the size of the loan further the purchase of a house provides an accurate measure of a relatively large fraction of consumption services obtained for a medium to long horizon and measured at the time of the consumption decision although our data also have some serious shortcomings they allow a look at the lcpi from an unconventional vantage point perhaps the most influential study employing the standard consumer survey in testing the lcpi at the micro level is that of hall and mishkin 1982 it examines food expenditure from the panel study of income dynamics one of their key results is that consumption tracks income more closely than would be expected under the lcpi they demonstrate that this result could be explained by assuming a group of liquidity constrained consumers consuming their income at each point in time of 20 of the total sample some of the drawbacks of this study are the use of food expenditures to represent consumption the underreporting of income and absence of proper wealth data inherent in the consumer survey and the associated inability to individually separate liquidity constrained consumers from the rest of the sample several previous studies have attempted to improve on this way of testing the lcpi by examining other data sets bernanke 1984 used data on durable consumption goods automobiles to overcome the drawbacks of using food consumption in the hall and mishkin study his results support the lcpi but are still suspect because of possible reporting biases and the lack of good wealth and savings observations

risky business multinationals uncertainty and asymmetric insurance a partial equilibrium model is used to examine the international production allocation of a two plant multinational firm that is confronted with uncertainty with respect to foreign sales the firm produces identical products in both plants using firm specific factors the internationally price discriminating multinational has monopoly power in both segmented markets the analysis focuses on how asymmetric insurance facilities between the firm s home and host country influence its international production allocation and level of intra firm trade

two step estimation and inference with possibly many included covariates we study the implications of including many covariates in a first step estimate entering a two step estimation procedure we find that a first order bias emerges when the number of included covariates is large relative to the square root of sample size rendering standard inference procedures invalid we show that the jackknife is able to estimate this many covariates bias consistently thereby delivering a new automatic bias corrected two step point estimator the jackknife also consistently estimates the standard error of the original two step point estimator for inference we develop a valid post bias correction bootstrap approximation that accounts for the additional variability introduced by the jackknife bias correction we find that the jackknife bias corrected point estimator and the bootstrap post bias correction inference perform excellent in simulations offering important improvements over conventional two step point estimators and inference procedures which are not robust to including many covariates we apply our results to an array of distinct treatment effect policy evaluation and other applied microeconomics settings in particular we discuss production function and marginal treatment effect estimation in detail

macroeconomic uncertainty precautionary saving and the current account abstract the relationship between current account developments and changes in the macroeconomic environment is a key issue in open economy macroeconomics this paper extends the standard intertemporal model of the current account to incorporate the effects of macroeconomic uncertainty on external saving behavior it is shown that the greater the uncertainty in national cash flow defined as output less investment less government consumption the greater will be the incentive for precautionary saving and ceteris paribus the larger the current account surplus empirical support for the model is found using post war quarterly data for the united states japan and the united kingdom as well as a long time series 1919 1990 for the united states

a generalization of pratt arrow measure to nonexpected utility preferences and inseparable probability and utility the pratt arrow measure of local risk aversion is generalized for then dimensional state preference model of choice under uncertainty in which the decision maker may have inseparable subjective probabilities and utilities unobservable stochastic prior wealth and or smooth nonexpected utility preferences local risk aversion is measured by the matrix of derivatives of the decision maker s risk neutral probabilities without reference to true subjective probabilities or riskless wealth positions and comparative risk aversion is measured without requiring agreement on true probabilities risk neutral probabilities and their derivatives are shown to be sufficient statistics for approximately optimal investment and financing decisions in complete markets for contingent claims

moral hazard and background risk in competitive insurance markets we examine the effect of background risk on competitive insurance markets with moral hazard if policy holders have non negative prudence then background risk does not decrease effort and when effort increases expands the set of feasible policies however the effect of background risk on equilibrium is indeterminate we analyse the choice between stock and mutual insurance mutual insurance is equivalent to a fair policy plus background risk our results imply that competitive insurance markets with moral hazard should be dominated by stock insurers

equilibrium consumption and precautionary savings in a stochastically growing economy abstract the derivation of a closed form solution for consumption based on the constant elasticity utility function in the presence of stochastic labor income has proved to be intractable this paper derives a closed form equilibrium relationship between consumption and wealth one that holds along a balanced growth path in a stochastic romer endogenous growth model by employing more general recursive preferences we can disentangle the coefficient of relative risk aversion from the intertemporal elasticity of substitution the effects of key structural parameters on equilibrium consumption and its tradeoff with leisure are analyzed a significant aspect of our analysis concerns the extent to which current risk in the economy is shared between labor and capital this plays an important role in determining the impact of risk on the economy in general and on consumption in particular formal analysis is supplemented with extensive numerical simulations

the interpretation of instrumental variables estimators in simultaneous equations models with an application to the demand for fish in markets where prices are determined by the intersection of supply and demand curves standard identification results require the presence of instruments that shift one curve but not the other these results are typically presented in the context of linear models with fixed coefficients and additive residuals the first contribution of this paper is an investigation of the consequences of relaxing both the linearity and the additivity assumption for the interpretation of linear instrumental variables estimators without these assumptions the standard linear instrumental variables estimator identifies a weighted average of the derivative of the behavioural relationship of interest a second contribution is the formulation of critical identifying assumptions in terms of demand and supply at different prices and instruments rather than in terms of functional form specific residuals our approach to the simultaneous equations problem and the average derivative interpretation of instrumental variables estimates is illustrated by estimating the demand for fresh whiting at the fulton fish market strong and credible instruments for identification of this demand function are available in the form of weather conditions at sea

alternative approaches to comparative nth degree risk aversion this paper extends the three main approaches to comparative risk aversion the risk premium approach and the probability premium approach of pratt 1964 risk aversion in the small and in the large

decreasing absolute prudence characterization and applications to second best risk sharing abstract in this paper we provide two basic properties of utility functions u which exhibit decreasing absolute prudence i e u u 0 these properties are used to examine the allocation of risks in an economy when some agents bear non transferable risks we show that it is fair pareto efficient to let those with a non transferable risk bear relatively less of the transferable risk in the economy if and only if absolute prudence is decreasing in another model there is a complete set of contingent markets but some agents have no direct access to them we examine the fair efficient allocation of risk in a pool gathering a trader and a non trader decreasing absolute prudence provides an upper bound to the share of the pool s risk that should be borne by the trader

imperfect insurance and differing propensities to consume across households abstract this paper extends previous tests of consumption insurance by splitting the sample to examine whether the marginal propensity to consume mpc out of idiosyncratic income shocks is larger for low wealth households than it is for high wealth households using data from the psid i find 1 the mpc of low wealth households is higher than that of high wealth households there are indications that both precautionary savings behavior and liquidity constraints contribute to this difference 2 splitting the data using two different measures of wealth indicates that households perceive housing equity as illiquid 3 when low wealth households are split into two subgroups the mpc of the very low wealth group is smaller reflecting the insurance aspects of means tested safety net programs

does the optimal size of a fish stock increase with environmental uncertainties we analyze the effect of environmental uncertainties on optimal fishery management in a bio economic fishery model unlike most of the literature on resource economics but in line with ecological models we allow the different biological processes of survival and recruitment to be affected differently by environmental uncertainties we show that the overall effect of uncertainty on the optimal size of a fish stock is ambiguous depending on the prudence of the value function for the case of a risk neutral fishery manager the overall effect depends on the relative magnitude of two opposing effects the convex cost effect and the gambling effect we apply the analysis to the baltic cod and the north sea herring fisheries concluding that for risk neutral agents the net effect of environmental uncertainties on the optimal size of these fish stocks is negative albeit small in absolute value under risk aversion the effect on optimal stock size is positive for sufficiently high coefficients of constant relative risk aversion

priority setting in health care and higher order degree change in risk this paper examines how priority setting in health care expenditures is influenced by the presence of uncertainty about the severity of the illness and the effectiveness of medical treatment we provide necessary and sufficient conditions on social preferences under which a social planner will allocate more health care resources to populations at higher risk changes in risk are defined by the concept of stochastic dominance up to order n the shape of the social utility function and an equity weighting function are used to model the inequality aversion of the social planner we show that for higher order risk changes the usual conditions on preferences such as prudence or relative risk aversion are not necessarily required to prioritise health care when there are different levels of uncertainty associated with otherwise similar patient groups

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

incomplete markets labor supply and capital accumulation we explore the accumulation of capital in the presence of limited insurance against idiosyncratic shocks borrowing constraints and endogenous labor supply in the exogenous labor supply case e g aiyagari 1994 huggett 1997 the presence of limited insurance increases the demand for savings for precautionary reasons as a consequence capital and output are higher under incomplete markets we show that if labor hours are endogenous labor supply is likely to be lower under incomplete markets because those agents who experience a high shock to productivity are ex post richer and they work fewer hours in some cases this wealth effect can overcome the aggregate precautionary savings and give rise to lower savings and output under incomplete

portfolio choice under noisy asset returns abstract the lack of a clear effect of increases in risk upon the demand for risky assets has led to many restrictions on the types of risk increases and or on consumer preferences in order to obtain unambiguous comparative statics this paper examines the particularly simple yet overlooked case of white noise added to the return distribution it is shown that kimball s standard risk aversion is sufficient for noise to lead to reduced demand for risky assets

estimating marginal returns to education this paper estimates marginal returns to college for individuals induced to enroll in college by different marginal policy changes the recent instrumental variables literature seeks to estimate this parameter but in general it does so only under strong assumptions that are tested and found wanting we show how to utilize economic theory and local instrumental variables estimators to estimate the effect of marginal policy changes our empirical analysis shows that returns are higher for individuals with values of unobservables that make them more likely to attend college we contrast our estimates with iv estimates of the return to schooling

buffer stock savings by portfolio adjustment evidence from rural india the empirical literature on household savings tends to treat savings simply as the residual of income minus consumption this article takes a unique approach to reconstruct the cash and asset balances using detailed household transaction data on farm households in rural india and generates monthly and seasonal icrisat panel data for the period 1976 1983 we have found that households irrespective of their landholding status cope with temporary shocks quite well by using crop inventory currency and capital assets rather than livestock as buffer assets the importance of portfolio adjustments in smoothing consumption is also confirmed by the use of a system of equations in which both portfolio and production decisions are made endogenous it is concluded that not only the level but also the diversification of household assets are important for buffering consumption as an extension we have explored the monthly icrisat panel data for the period 2009 2012 in the same villages and have found a similar pattern in household portfolio responses to income shocks

unemployment fears and deflationary spirals the interaction of incomplete markets and sticky nominal wages is shown to magnify business cycles even though these two features in isolation dampen them during recessions fears of unemployment stir up precautionary sentiments which induces agents to save more the additional savings may be used as investments in both a productive asset equity and an unproductive asset money but even a small rise in money demand has important consequences the desire to hold money puts deflationary pressure on the economy which provided that nominal wages are sticky increases wage costs and reduces firm profits lower profits repress the desire to save in equity which increases the fear of unemployment and so on this is a powerful mechanism which causes the model to behave differently from both its complete markets version and a version with incomplete markets but without aggregate uncertainty in contrast to previous results in the literature agents uniformly prefer non trivial levels of unemployment insurance

optimal bidding and hedging in international markets this paper examines the optimal bidding and hedging decisions of a risk averse contractor for a construction project abroad we show that currency options play no role as a hedging instrument when the contractor has a quadratic utility function however if the contractor is prudent currency options are used for hedging purposes prudence thus generates a hedging demand for currency options when foreign exchange exposure is uncertain contrary to the conventional wisdom we show that currency hedging may have perverse effects on the contractor s bidding behavior in a canonical example with negative exponential utility functions we demonstrate that the possibilities for the contractor to bid more aggressively in the absence of currency hedging are not factitious

risk lovers and the rent over investment puzzle in this paper we prove existence and uniqueness of equilibrium in a rent seeking contest given a class of heterogeneous risk loving players we explore the role third order risk attitude plays in equilibrium and find that imprudence is sufficient for risk lovers to increase rent seeking investment above the risk neutral outcome moreover we show that rent can be fully dissipated in a standard tullock contest played by a large number of risk lovers

mean variance skewness portfolio performance gauging a general shortage function and dual approach this paper proposes a nonparametric efficiency measurement approach for the static portfolio selection problem in mean variance skewness space a shortage function is defined that looks for possible increases in return and skewness and decreases in variance global optimality is guaranteed for the resulting optimal portfolios we also establish a link to a proper indirect mean variance skewness utility function for computational reasons the optimal portfolios resulting from this dual approach are only locally optimal this framework permits to differentiate between portfolio efficiency and allocative efficiency and a convexity efficiency component related to the difference between the primal nonconvex approach and the dual convex approach furthermore in principle information can be retrieved about the revealed risk aversion and prudence of investors an empirical section on a small sample of assets serves as an illustration

optimal insurance against climatic experience an optimal insurance contract against a climatic risk is derived in the presence of an uninsurable and dependent aggregate production risk the optimaldesign depends on the stochastic dependency between both sources of uncertainty and on the producer s attitude towards risk especially on his prudent behavior rationalweather insurance purchasing decisions are al so derived the prudent producer responds to actuarially fair weather insurance by increasing his exposure towards risk the u s multiple peril crop insurance program in which indemnity payments are based on the producer s individualyiel ds has been disappointing in that premiums have not been sufficient to cover indemnity payments and administrative costs this failure has induced the u s government to promote alternative insurance policies since 1993 the risk management agency has offered areayield contracts under its group risk plan in selected counties skees black and barnett another alternative is to base the indemnity on a weather index such as rainfall or temperature this policy was proposed in the past by sanderson but has failed to gain acceptance among policy makers the difficulties of rainfall insurance were a subject of debate in australia e g bardsley abey and davenport quiggin 1986 patrick the recent development of weather based instruments on financialmarkets known as weather derivatives for which the payoff depends on the cause of risk rather than on its effect on yield provide new opportunities for covering exposure to unfavorable weather events the objective of this article is threefold first a stochastic production function affected by a climatic risk and by an aggregate production risk where both sources of risk are stochastically dependent is de

optimal random monetary policy with nominal rigidity abstract this paper studies a money in the utility function model with imperfect competition and one period ahead nominal price setting under standard assumptions on preferences friedman s rule setting the money growth rate equal to the household time discount factor generates an equilibrium that is optimal within the class of deterministic policies we then provide conditions under which a random monetary policy increases ex ante expected welfare relative to friedman s rule the result obtains because random policy can reduce the distortion associated with imperfect competition our result exhibits original features relative to existing cases of welfare improving random monetary policy such as polemarchakis and weiss j econom theory 15 1977 345

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

prudence in bargaining the effect of uncertainty on bargaining outcomes abstract we investigate the outcome of bargaining when a player s pay off from agreement is risky we find that a risk averse player typically increases his equilibrium receipts when his pay off is made risky this is because the presence of risk makes individuals behave more patiently in bargaining strong analogies are drawn to the precautionary saving literature we show that the effect of risk on receipts can be sufficiently strong that a decreasingly risk averse player may be better off receiving a risky pay off than a certain pay off

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

are risk preferences stable across contexts evidence from insurance data using a unique dataset we test whether households deductible choices in auto and home insurance reflect stable risk preferences our test relies on a structural model that assumes households are objective expected utility maximizers and claims are generated by household coverage specific poisson processes we find that the hypothesis of stable risk preferences is rejected by the data our analysis suggests that many households exhibit greater risk aversion in their home deductible choices than their auto deductible choices our results are robust to several alternative modeling assumptions jel d11 d83

designing optimal crop revenue insurance when the indemnity schedule is contingent on the farmer s price and individual yield an optimal crop revenue insurance contract depends only on the farmer s gross revenue however this design is not efficient if as is the case with available contracts the coverage function is based on imperfect estimators of individual yield and or price the producer s degree of prudence and the extent of basis risks have important influences on the optimal indemnity schedule in this broader context optimal protection is not provided by available u s crop insurance contracts and may include combinations of revenue insurance yield insurance futures and options contracts

revisiting precautionary saving under ambiguity abstract i study the two period consumption saving problem with non separable utility under ambiguity under smooth ambiguity aversion ambiguity and greater ambiguity aversion raise optimal saving when relative prudence in ambiguity preferences does not exceed 2 agents who perceive greater ambiguity have a higher demand for saving while a convex marginal ambiguity function is not sufficient for precautionary saving in time separable models berger 2014 i show that it is not even necessary in a time non separable setting

prudence and risk vulnerability in two moment decision models abstract prudence risk vulnerability temperance and some related concepts have recently been introduced into the expected utility framework of decision making under uncertainty we demonstrate how they can be meaningfully formulated in terms of two moment mean standard deviation preferences

intertemporal choice and consumption mobility the theory of intertemporal consumption choice makes sharp predictions about the evolution of the entire distribution of household consumption not just about its conditional mean in the paper we study the empirical transition matrix of consumption using a panel drawn from the bank of italy survey of household income and wealth we estimate the parameters that minimize the distance between the empirical and the theoretical transition matrix of the consumption distribution the transition matrix generated by our estimates matches remarkably well the empirical matrix both in the aggregate and in samples stratified by education our estimates strongly reject the consumption insurance model and suggest that households smooth income shocks to a lesser extent than implied by the permanent income hypothesis jel d52 d91 i30

precautionary saving an explanation for excess sensitivity of consumption the permanent income hypothesis under certainty equivalence yields a martingale consumption process empirically this hypothesis is rejected because consumption is excessively sensitive to anticipated income one approach to account for excess sensitivity is to relax certainty equivalence by using utility functions that induce precautionary saving this article analyzes a hyperbolic absolute risk aversion utility function empirically some reasonable parameterizations of this specification allow one to match the excess sensitivity associated with the data these parameterizations also permit one to account for the excess smoothness problem excess sensitivity and excess smoothness however do not reflect the same phenomenon

precautionary wealth accumulation this paper provides theoretical foundations for when individual and aggregate wealth accumulation increase as earnings risk increases stated in terms of a simple picture the problem addressed in this paper is to find sufficient conditions such that the pattern in figure 1 holds figure 1 describes a situation in which an individual s expected wealth accumulation profile is weakly greater at each age over the life cycle whenever the individual faces one earnings process that is riskier than another earnings process other things equal two important open questions can be answered by finding sufficient conditions for the pattern in figure 1 to occur first there is the question of when theory predicts that households that face more earnings risk have more expected wealth accumulation at any point in the life cycle than households that face less earnings risk the development of such a theory would be helpful as there is a sizeable empirical literature related to this question which is surveyed by browning and lusardi 1996 second there is the question of when theory predicts that aggregate wealth accumulation increases as earnings risk increases much of the interest in the precautionary savings literature is based on the possibility that an important part of aggregate wealth is due to uninsured earnings risk this question can also be answered with figure 1 the idea is to treat the expected wealth profile of one individual as the realized average wealth profile of a large number of similarly situated individuals the law of large numbers justifies this when shocks are independent across individuals and thus earnings risk is idiosyncratic since aggregate wealth holding is a weighted sum of the average wealth holdings of individuals at different ages an upward shift of the expected wealth profile of all agents then implies that aggregate wealth holding increases with increases in earnings risk other things equal this paper provides the first general answer to when the pattern in figure 1 occurs in the context of a multi period model with independent earnings shocks the answer is given at two levels in terms of properties of the decision rule for savings i e the savings function and in terms of preferences a savings function maps an individual s current state e g current wealth and earnings and age into savings or wealth carried into the next model period given a specific earnings process since economists are familiar with the merits of sufficient conditions stated in terms of preferences i will try to motivate why sufficient conditions stated in terms of the savings function are interesting first they are widely applicable they apply to theories where savings decisions maximize a utility function or are given by a rule of thumb they also apply to models where there is wage risk and there are both consumption saving and labour leisure decisions second in so far as the savings function can be estimated it is useful for an empirical

the distribution of wealth with uncertain income it is well known that an uncertain income stream will induce individuals to save if they are forward looking in this paper we investigate the consequences of such saving on the distribution of wealth among households the inquiry is motivated by the fact that both the dispersion of the us wealth distribution and the variance of transitory income have increased in the recent past surprisingly we find that an increase in earnings uncertainty is more likely to decrease than increase the inequality in wealth holdings

do risk lovers invest in self protection we show that there is a class of risk lovers who optimally choose a positive level of self protection investment in most cases a risk lover increases his self protection investment as he becomes less downside risk averse

monetary policy by committee consensus chairman dominance or simple majority this paper studies the theoretical and empirical implications of monetary policy making by committee under four different voting protocols the protocols are a consensus model where a supermajority is required for a policy change an agenda setting model where the chairman controls the agenda a dictator model where the chairman has absolute power over the committee and a simple majority model where policy is determined by the median member these protocols give preeminence to different aspects of the actual decision making process and capture the observed heterogeneity in formal procedures across central banks the models are estimated by maximum likelihood using interest rate decisions by the committees of five central banks namely the bank of canada the bank of england the european central bank the swedish riksbank and the u s federal reserve for all central banks results indicate that the consensus model fits actual policy decisions better than the alternative models this suggests that despite institutional differences committees share unwritten rules and informal procedures that deliver observationally equivalent policy decisions

does consumption respond to predicted increases in cash hand availability evidence from the italian severance pay abstract we examine whether italian household consumption exhibits excess sensitivity to severance pay a sizable lump sum that workers receive at job termination we find no evidence of excess sensitivity of non durable expenditure to this anticipated cash in hand change

stochastic dominance analysis without the independence axiom we characterize the consistency of a large class of nonexpected utility preferences including mean variance preferences and prospect theory preferences with stochastic orders for example stochastic dominances of different degrees our characterization rests on a novel decision theoretic result that provides a behavioral interpretation of the set of all derivatives of the functional representing the decision maker s preferences as an illustration we consider in some detail prospect theory and choice acclimating preferences two popular models of reference dependence under risk and we show the incompatibility of loss aversion with prudence this paper was accepted by james smith decision analysis

risk and savings a taxonomy abstract the effect of risk on savings depends not just on preferences but also on the type of risk this helps to explain why the empirical literature reports positive effects for developed countries but negative effects for developing countries

uncertainty and consumer durables adjustment we characterize infrequent durables stock adjustment by consumers who also derive utility from non durable consumption flows in the presence of idiosyncratic income uncertainty the data we analyse include subjective future income uncertainty measures which we use as instruments in the estimation of relevant parameters of heterogeneous consumers dynamic adjustment problems the data feature two conceptually distinct sources of variation cross sectional heterogeneity of the sampled households dynamic problems and history dependent heterogeneity in their situation during the observation period we note that the latter should affect the likelihood but not the size of stock adjustment decisions and find broad support for theoretical predictions in formal selection controlled regressions based on this insight

have filipino households become less prudent abstract throughout the 2000s the average household saving rate in the philippines declined sharply this article explains why households consumption growth has been higher than income growth during this period tracing cohorts shows that saving declined across all demographic groups a test that provides the strength of the precautionary saving motive yields a plausible explanation that households have become financially constrained and less prudent in recent years this article argues that these patterns are best explained by the extended coverage of the social security system particularly to informal sector employees during the 1990s in the philippines

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