Dynamic Portfolio Choice with Stochastic Wage and Life Insurance

We study optimal insurance, consumption, and portfolio choice in a framework where a family purchases life insurance to protect the loss of the wage earner's human capital. Explicit solutions are obtained by employing constant absolute risk aversion utility functions. We show that the optimal life insurance purchase is not a monotonic function of the correlation between the wage and the financial market. Meanwhile, the life insurance decision is explicitly affected by the family's risk preferences in general. The model also predicts that a family uses life insurance and investment portfolio choice to hedge stochastic wage risk.     

Dynamic Consumption and Portfolio Choice with Stochastic Volatility in Incomplete Markets

This paper examines the optimal consumption and portfolio-choiceproblem of long-horizon investors who have access to a risklessasset with constant return and a risky asset ("stocks") withconstant expected return and time-varying precision—thereciprocal of volatility. Markets are incomplete, and investorshave recursive preferences defined over intermediate consumption.The paper obtains a solution to this problem which is exactfor investors with unit elasticity of intertemporal substitutionof consumption and approximate otherwise. The optimal portfoliodemand for stocks includes an intertemporal hedging componentthat is negative when investors have coefficients of relativerisk aversion larger than one, and the instantaneous correlationbetween volatility and stock returns is negative, as typicallyestimated from stock return data. Our estimates of the jointprocess for stock returns and precision (or volatility) usingU.S. data confirm this finding. But we also find that stockreturn volatility does not appear to be variable and persistentenough to generate large intertemporal hedging demands.     

Losing Money on Arbitrage: Optimal Dynamic Portfolio Choice in Markets with Arbitrage Opportunities

We derive the optimal investment policy of a risk-averse investorin a market where there is a textbook arbitrage opportunity,but where liabilities must be secured by collateral. We findthat it is often optimal to underinvest in the arbitrage bytaking a smaller position than collateral constraints allow.Even when the optimal policy is followed, the arbitrage portfoliotypically experiences losses before the final convergence date.In fact, its initial performance may be indistinguishable fromthat of a conventional portfolio with a poor track record. Theseresults have important implications for the role of arbitrageursin financial markets.     

Economic Value Added,Future Accounting Earnings,and Financial Analysts' Earnings Per Share Forecasts

Empirical research to date on the relative effectiveness of Economic Value Added (EVA) and earnings per share (EPS) as measures of firm performance for stock valuation has been mixed. In contrast to prior research, which primarily focuses on the correspondence of these measures with shareholder value and changes therein, we examine their relative effectiveness in predicting future earnings and their role in enhancing the accuracy of analysts' forecasts. Our results indicate that EVA contains information that is incremental to EPS in predicting future earnings. In addition, we find that despite this potential for EVA to add incremental value to analysts' forecasts of future earnings, analysts do not use the information in reported EVA appropriately, but appear rather to overweigh it.     

Intertemporal Resolution of Uncertainty and Portfolio Behavior

In this paper, it is shown that the early resolution of uncertainty improves the welfare of an investor who has utility defined over his intertemporal consumption. This result arises because the early resolution of uncertainty permits the investor the additional flexibility of rearranging his initial consumption. In contrast, if the investor has utility for terminal wealth, there is no effect on his portfolio behavior from the early resolution of uncertainty.     

The Impact of Publication of Analysts' Recommendations on Returns and Trading Volume

Publication of security analysts' recommendations in the column “Inside Wall Street,” which is published in Business Week, induces abnormal returns on the publication day and the following day. The abnormal returns are robust to the use of alternative samples and methodologies. The publication increases trading volumes for the securities that are recommended to be purchased, but not for securities that are recommended to be sold. The abnormal returns and trading volumes support the view that stock prices do not adjust instantaneously when new information arrives, and that the time pattern of price adjustment depends on the time pattern of the accessibility of the information. The authors find no statistically significant difference between the average abnormal returns that are induced by recommendations that appear at the beginnings of “Inside Wall Street” columns (and are covered more extensively than others) and the average abnormal returns induced by other recommendations.     

A Simulation Approach to Dynamic Portfolio Choice with an Application to Learning About Return Predictability

We present a simulation-based method for solving discrete-timeportfolio choice problems involving non-standard preferences,a large number of assets with arbitrary return distribution,and, most importantly, a large number of state variables withpotentially path-dependent or non-stationary dynamics. The methodis flexible enough to accommodate intermediate consumption,portfolio constraints, parameter and model uncertainty, andlearning. We first establish the properties of the method forthe portfolio choice between a stock index and cash when thestock returns are either iid or predictable by the dividendyield. We then explore the problem of an investor who takesinto account the predictability of returns but is uncertainabout the parameters of the data generating process. The investorchooses the portfolio anticipating that future data realizationswill contain useful information to learn about the true parametervalues.     

Commercial Bank Portfolio Behavior and Endogenous Uncertainty

This paper demonstrates how Bayesian information may be analyzed as a variable input in determining an optimal bank portfolio and investigates the impact of information in a way that is statistically satisfactory. A portfolio model is developed, and the impact of information is analyzed. Information is treated as an economic input that is used up to the point where its predicted marginal benefit is exactly equal to its marginal cost, and, from there, the optimal demand for information is derived. A comparative-static analysis demonstrates that the reaction of optimal portfolio holdings to interest rate changes under variable uncertainty is dramatically different from portfolio behavior when uncertainty is exogenous. Finally, the elasticity of reserves with respect to scale is examined under the assumption of variable uncertainty.     

Correlation Risk and Optimal Portfolio Choice

We develop a new framework for multivariate intertemporal portfolio choice that allows us to derive optimal portfolio implications for economies in which the degree of correlation across industries, countries, or asset classes is stochastic. Optimal portfolios include distinct hedging components against both stochastic volatility and correlation risk. We find that the hedging demand is typically larger than in univariate models, and it includes an economically significant covariance hedging component, which tends to increase with the persistence of variance–covariance shocks, the strength of leverage effects, the dimension of the investment opportunity set, and the presence of portfolio constraints.     

Systemic Risk and International Portfolio Choice

Returns on international equities are characterized by jumps; moreover, these jumps tend to occur at the same time across countries leading to systemic risk. We capture these stylized facts using a multivariate system of jump‐diffusion processes where the arrival of jumps is simultaneous across assets. We then determine an investor's optimal portfolio for this model of returns. Systemic risk has two effects: One, it reduces the gains from diversification and two, it penalizes investors for holding levered positions. We find that the loss resulting from diminished diversification is small, while that from holding very highly levered positions is large.     

Portfolio Choice in the Presence of Housing

I show that investment in housing plays a crucial role in explainingthe patterns of cross-sectional variation in the compositionof wealth and the level of stockholdings observed in portfoliocomposition data. Due to investment in housing, younger andpoorer investors have limited financial wealth to invest instocks, which reduces the benefits of equity market participation.House price risk crowds out stockholdings, and this crowdingout effect is larger for low financial net-worth. In the modelas in the data leverage is positively correlated with stockholdings.     

Hedging, Familiarity and Portfolio Choice

We exploit the restrictions of intertemporal portfolio choicein the presence of nonfinancial income risk to test hedgingusing the information contained in the actual portfolio of theinvestor. We use a unique data set of Swedish investors withinformation broken down at the investor level and into variouscomponents of investor wealth, income, and demographic characteristics.Portfolio holdings are identified at the stock level. We showthat investors do not hedge but invest in stocks closely relatedto their nonfinancial income. We explain this with familiarity,that is, the tendency to concentrate holdings in stocks to whichthe investor is geographically or professionally close or thathe has held for a long period. We show that familiarity is nota behavioral bias, but is information driven. Familiarity-basedinvestment allows investors to earn higher returns than theywould have otherwise earned if they had hedged.     

Dynamic Effects of Financial Openness on Economic Growth and Macroeconomic Uncertainty

This paper examines the dynamic effects of financial integration and foreign direct investment (FDI) on economic growth and macroeconomic uncertainty. Using the pooled mean group autoregressive distributed lag approach to annual data over 1975-2007 for ninety developing countries, we find that financial integration contributes to faster economic growth and lower growth uncertainty in the long run. The evidence also shows considerable heterogeneity in the short run. In addition, we find that FDI impedes output growth but mitigates uncertainty in output and consumption growth in the long run. In the short run, FDI has an average negative effect on growth and negligible effect on growth uncertainty, but there are large cross-country differences in response to FDI integration.     

Consumption and Portfolio Choice over the Life Cycle

This article solves a realistically calibrated life cycle modelof consumption and portfolio choice with non-tradable laborincome and borrowing constraints. Since labor income substitutesfor riskless asset holdings, the optimal share invested in equitiesis roughly decreasing over life. We compute a measure of theimportance of human capital for investment behavior. We findthat ignoring labor income generates large utility costs, whilethe cost of ignoring only its risk is an order of magnitudesmaller, except when we allow for a disastrous labor incomeshock. Moreover, we study the implications of introducing endogenousborrowing constraints in this incomplete-markets setting.     

The Pricing of Event Risks with Parameter Uncertainty

Financial instruments whose payoffs are linked to exogenous events, such as the occurrence of a natural catastrophe or an unusual weather pattern depend crucially on actuarial models for determining event (e.g., default) probabilities. In many instances, investors appear to receive premiums far in excess of these modeled actuarial probabilities, even for event risks that are uncorrelated with returns on other financial assets. Some have attributed these larger spreads to uncertainty in the probabilities generated by the models. We provide a simple model of such parameter uncertainty and demonstrate how it affects rational investors' demand for event risk exposures. We show that while parameter uncertainty does indeed affect bond spreads, it does not tend to increase spreads by much. Indeed, the spread increases due to parameter uncertainty in our numerical examples are on the order of only 1–2 basis points. Moreover, in many instances, including those that have the most sensible correlation settings, parameter uncertainty tends to decrease the size of bond spreads. We therefore argue that parameter uncertainty does not appear to be a satisfactory explanation for high event-risk returns.     

Learning about Predictability: The Effects of Parameter Uncertainty on Dynamic Asset Allocation

This paper examines the effects of uncertainty about the stock return predictability on optimal dynamic portfolio choice in a continuous time setting for a long-horizon investor. Uncertainty about the predictive relation affects the optimal portfolio choice through dynamic learning, and leads to a state-dependent relation between the optimal portfolio choice and the investment horizon. There is substantial market timing in the optimal hedge demands, which is caused by stochastic covariance between stock return and dynamic learning. The opportunity cost of ignoring predictability or learning is found to be quite substantial.     

The Effect of Housing on Portfolio Choice

We show that characterizing the effects of housing on portfolios requires distinguishing between the effects of home equity and mortgage debt. We isolate exogenous variation in home equity and mortgages by using differences across housing markets in house prices and housing supply elasticities as instruments. Increases in property value (holding home equity constant) reduce stockholdings, while increases in home equity wealth (holding property value constant) raise stockholdings. The stock share of liquid wealth would rise by 1 percentage point—6% of the mean stock share—if a household were to spend 10% less on its house, holding fixed wealth.     

Portfolio Choice in the Presence of Personal Illiquid Projects

Personal projects, such as a private business or the purchase of a home, influence individuals' portfolio choice. We conduct a theoretical analysis of this influence when financial assets are required to provide liquidity to personal projects. Due to this liquidity consideration, individuals behave in a more risk-averse fashion when there is a large penalty for discontinuing or underinvesting in the final stages of the projects. In addition, using data from the 1995 Survey of Consumer Finances, we find that households that are saving to invest in their own businesses or in their own homes indeed have significantly safer financial portfolios.     

Wealth, Information Acquisition, and Portfolio Choice

I solve (with an approximation) a Grossman-Stiglitz economyunder general preferences, thus allowing for wealth effects.Because information generates increasing returns, decreasingabsolute risk aversion, in conjunction with the availabilityof costly information, is sufficient to explain why wealthierhouseholds invest a larger fraction of their wealth in riskyassets. One no longer needs to resort to decreasing relativerisk aversion, an empirically questionable assumption. Furthermore,I show how to distinguish empirically between these two explanations.Finally, I find that the availability of costly informationexacerbates wealth inequalities.     

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.