Precautionary Saving and Consumption Smoothing across Time and Possibilities

This paper examines how aversion to risk and aversion to intertemporal substitution determine the strength of the precautionary saving motive in a two-period model with Selden/Kreps–Porteus preferences. For small risks, we derive a measure of the strength of the precautionary saving motive that generalizes the concept of "prudence" introduced by Kimball (1990b) . For large risks, we show that decreasing absolute risk aversion guarantees that the precautionary saving motive is stronger than risk aversion, regardless of the elasticity of intertemporal substitution. Holding risk preferences fixed, the extent to which the precautionary saving motive is stronger than risk aversion increases with the elasticity of intertemporal substitution. We derive sufficient conditions for a change in risk preferences alone to increase the strength of the precautionary saving motive and for the strength of the precautionary saving motive to decline with wealth. Within the class of constant elasticity of intertemporal substitution, constant-relative risk aversion utility functions, these conditions are also necessary.     

Robust consumption and portfolio choice for time varying investment opportunities

This paper examines a continuous-time intertemporal consumption and portfolio choice problem for an investor with recursive preferences. The investor worries about model misspecification and seeks robust decision rules. The expected excess return of a risky asset follows a mean-reverting process. I find that whether the concern about model misspecification decreases the total demand for equities largely depends on risk aversion and the attitude toward intertemporal substitution. When the elasticity of intertemporal substitution is about 1 and risk aversion is moderate, the aversion to model uncertainty increases the proportion of wealth invested in equities. The calibration analysis based on detection-error probabilities shows that the quantitative effect of robustness is almost negligible.     

Asset pricing in production economies with extrapolative expectations

Introducing extrapolative bias into a standard production-based model with recursive preferences reconciles salient stylized facts about business cycles (low consumption volatility, high investment volatility relative to output) and financial markets (high equity premium, volatile stock returns, low and smooth risk-free rate) with plausible levels of risk aversion and intertemporal elasticity of substitution. Furthermore, the model captures return predictability based upon dividend yield, Q, and investment. Intuitively, extrapolative bias increases the variation in the wealth–consumption ratio, which is heavily priced under recursive preferences; adjustment costs decrease the covariance between marginal utility and asset returns. Empirical support for key implications of the model is also provided.     

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.     

Rare events and annuity market participation

We investigate whether a rare event (like the default of the annuity provider) can explain the annuity market participation puzzle. High risk aversion is needed to change behavior in the presence of such a disastrous shock but higher risk aversion also makes annuities more valuable. Therefore, these rare events are unlikely candidates to explain the low take-up of voluntary annuities: the conclusion is robust to disentangling risk aversion from intertemporal substitution and to allowing portfolio investment in a stock market index.     

Uncovering the Risk–Return Relation in the Stock Market

There is ongoing debate about the apparent weak or negative relation between risk (conditional variance) and expected returns in the aggregate stock market. We develop and estimate an empirical model based on the intertemporal capital asset pricing model (ICAPM) that separately identifies the two components of expected returns, namely, the risk component and the component due to the desire to hedge changes in investment opportunities. The estimated coefficient of relative risk aversion is positive, statistically significant, and reasonable in magnitude. However, expected returns are driven primarily by the hedge component. The omission of this component is partly responsible for the existing contradictory results.     

Consumption–investment optimization with Epstein–Zin utility in incomplete markets

In a market with stochastic investment opportunities, we study an optimal consumption–investment problem for an agent with recursive utility of Epstein–Zin type. Focusing on the empirically relevant specification where both risk aversion and elasticity of intertemporal substitution are in excess of one, we characterize optimal consumption and investment strategies via backward stochastic differential equations. The superdifferential of indirect utility is also obtained, meeting demands from applications in which Epstein–Zin utilities were used to resolve several asset pricing puzzles. The empirically relevant utility specification introduces difficulties to the optimization problem due to the fact that the Epstein–Zin aggregator is neither Lipschitz nor jointly concave in all its variables.     

Investment,idiosyncratic risk,and growth options

We provide evidence that growth options play an important role in determining the negative relation between corporate investment and idiosyncratic risk in the absence of agency problem. A simple real options model predicts that the negative relation between corporate investment and idiosyncratic risk is a U-shaped function of the level of idiosyncratic risk: investment responds the most when idiosyncratic risk is at the intermediate level. And the negative relation is stronger when firms possess more growth options. Our results are robust when we control for the effect of managerial risk aversion, supporting the view that firms’ optimal response to uncertainty is an important driving force behind the negative investment–idiosyncratic risk relation.     

Life insurance decisions under recursive utility

In this paper, we generalize recursive utility to include lifetime uncertainty and utility from bequest. The generalization applies to discrete-time as well as continuous-time recursive utility, and it is an important step forward in the development of recursive utility. We formalize the problem of optimal consumption, investment, and life insurance choice under recursive utility, and we state a verification theorem with a generalized Hamilton-Jacobi-Bellman equation. Our generalization of recursive utility allows us to study optimal consumption, investment, and life insurance choice under separation of (market) risk aversion, elasticity of inter-temporal substitution, and elasticity of substitution between bequest and future utility. The separation gives rise to hump-shaped consumption patterns as observed in realized consumption.     

Retirement,home production and labor supply elasticities

A standard life cycle model with home production implies a tight relationship between key preference parameters and the changes in time allocated to home production and leisure at retirement. We derive this relationship and use data from the ATUS to explore its quantitative implications. The key finding is that the intertemporal elasticity of substitution for leisure and the elasticity of substitution between time and goods in home production are approximately equal, in contrast to what is commonly assumed.     

Loss aversion and the asymmetric transmission of monetary policy

There is widespread evidence that monetary policy exerts asymmetric effects on output over contractions and expansions in economic activity, while price responses display no sizeable asymmetry. To rationalize these facts we develop a dynamic general equilibrium model where households’ utility depends on consumption deviations from a reference level below which loss aversion is displayed. State-dependent degrees of real rigidity and elasticity of intertemporal substitution in consumption generate competing effects on output and inflation. Contractions face the Central Bank with higher responsiveness of output to interest rate changes, as well as a flatter aggregate supply schedule.     

Insider Trading, Investment, and Liquidity: A Welfare Analysis

We compare equilibrium trading outcomes with and without participation by an informed insider, assuming inflexible ex ante aggregate investment choices by agents. Noise trading arises from aggregate uncertainty regarding other agents' intertemporal consumption preferences. The welfare levels of outsiders can thus be ascertained. The allocations without insider trading are not ex ante Pareto efficient, because our model differs from standard ones with negative exponential utility functions and normal returns. We characterize the circumstances under which the revelation of payoff-relevant information via prices—arising from insider trading—benefits outsiders with stochastic liquidity needs, by improving risk-sharing among them.     

Optimal savings distortions with recursive preferences

This paper derives an intertemporal optimality condition for economies with private information, focusing on a class of recursive preferences. By comparing it to the situation where agents can freely save in a risk-free asset market, we derive the optimal savings distortions necessary for constrained optimality. Our recursive preferences are homogeneous and satisfy a balanced-growth condition, while allowing us to separate the role of risk aversion and intertemporal elasticity of substitution. We perform some quantitative exercises that disentangle the respective roles played by these two parameters in optimal distortions and the implied welfare gains.     

Inflation,wealth and interest rates in an intertemporal optimizing model

This paper analyzes the relationship between the growth of the money supply and capital accumulation in a monetary optimizing model. Under certain conditions we show that a large intertemporal elasticity of substitution makes the nominal rates of interest undershoot its long-term value, that a low elasticity gives rise to overshooting, while a unitary elasticity is shown to make the nominal rate of interest a constant. These considerations plus explicit attention paid to the income and substitution effects induced by the changes in the nominal rates of interest provide us with an understanding of the correlation between growth of money and capital accumulation.     

The independence axiom and asset returns

This paper integrates models of atemporal risk preference that relax the independence axiom into a recursive intertemporal asset-pricing framework. The resulting models are amenable to empirical analysis using market data and standard Euler equation methods. We are thereby able to provide the first nonlaboratory-based evidence regarding the usefulness of several new theories of risk preference for addressing standard problems in dynamic economics. Using both stock and bond returns data, we find that a model incorporating risk preferences that exhibit first-order risk aversion accounts for significantly more of the mean and autocorrelation properties of the data than models that exhibit only second-order risk aversion. Unlike the latter class of models which require parameter estimates that are outside of the admissible parameter space, e.g., negative rates of time preference, the model with first-order risk aversion generates point estimates that are economically meaningful. We also examine the relationship between first-order risk aversion and models that employ exogenous stochastic switching processes for consumption growth.     

Reconciling conflicting evidence on the elasticity of intertemporal substitution: A macroeconomic perspective

In this paper we reconcile two opposing views about the elasticity of intertemporal substitution (EIS). Empirical studies using aggregate consumption data typically find the EIS to be close to zero, whereas calibrated models designed to match growth and fluctuations facts typically require it to be close to one. This contradiction is resolved when two kinds of heterogeneity are acknowledged: one, the majority of households do not participate in stock markets; and two, the EIS increases with wealth. We introduce these two features into a standard real business cycle model. First, limited participation creates substantial wealth inequality as in the U.S. data. Consequently, the properties of aggregates directly linked to wealth (e.g., investment and output) are mainly determined by the (high-EIS) stockholders. Since consumption is much more evenly distributed than is wealth, estimation from aggregate consumption uncovers the low EIS of the majority (i.e., the poor).     

Comparative Ambiguity Aversion in Intertemporal Decisions

This article examines the effects of ambiguity aversion on intertemporal decisions when there is ambiguity about a future state. Compared to the existing literature, we allow for a three-way separation between intertemporal substitution, risk aversion, and ambiguity aversion. Holding risk preferences, beliefs, and time preferences fixed, we explore how a change in ambiguity aversion increases the strength of the current willingness to pay. We apply our results to saving, self-protection, and self-insurance problems.     

Effects of uncertainty and risk aversion on the exposure of investment-style factor returns to real activity

How do uncertainty and risk aversion affect the behavior of investment-style factors? We argue that a significant channel through which both uncertainty and risk aversion impact aggregate risk factors is the exposure of factor returns to real activity. We analyze this issue using mixed data sampling decomposition of the sensitivity of factor returns to real activity into high- and low-frequency components. We find a positive and significant relation between uncertainty and risk aversion for the low-frequency component of the sensitivity of factor returns to economic activity. More importantly, risk aversion significantly amplifies the effects of uncertainty on real activity exposure. The quality-based factor is an important exception to these findings.     

Investment,Idiosyncratic Risk,and Ownership

High‐powered incentives may induce higher managerial effort, but they also expose managers to idiosyncratic risk. If managers are risk averse, they might underinvest when firm‐specific uncertainty increases, leading to suboptimal investment decisions from the perspective of well‐diversified shareholders. We empirically document that, when idiosyncratic risk rises, firm investment falls, and more so when managers own a larger fraction of the firm. This negative effect of managerial risk aversion on investment is mitigated if executives are compensated with options rather than with shares or if institutional investors form a large part of the shareholder base.