Sufficiency Conditions For Inclusion of One Asset Over Another in Investment Portfolios

By extending Tsiang's (1972) analysis to encompass two risky assets, sufficiency conditions for including one asset over another in any investor's investment portfolio are derived. This derivation stems from the fact that any realistic utility function must have indifference curves with slopes less than one. Using this model's framework, it is found that short-term Treasury bills in addition to cash balances cannot be a component of investor's investment portfolios. The results have implications for both the risk-free rate used in portfolio analysis and provide a partial solution to Mehra and Prescott's (1985) equity premium puzzle.     

Optimal allocation to hedge funds: an empirical analysis

What percentage of their portfolio should investors allocate to hedge funds? The only available answers to the above question are set in a static mean-variance framework, with no explicit accounting for uncertainty on the active manager's ability to generate abnormal return, and usually generate unreasonably high allocations to hedge funds. In this paper, we apply the model introduced in Cvitanic et al (2002b Working Paper USC) for optimal investment strategies in the presence of uncertain abnormal returns to a database of hedge funds. We find that the presence of the model risk significantly decreases an investor's optimal allocation to hedge funds. Another finding of this paper is that low beta hedge funds may serve as natural substitutes for a significant portion of investor risk-free asset holdings.     

A knowledge‐based framework for incorporating investor's preference into portfolio decision‐making

This paper describes a framework for the integration of a rule‐based system capable of identifying an investor's risk preference into a quantitative portfolio model based on risk and expected return. By inferring rules consisting of an investor's objective and subjective risk preferences, the integrated methodology provides the assets suitable for the preferences. Through investment in the portfolio composed of the assets, the investor is able to obtain the following bene?ts: reduction of costs and time spent to determine target assets, and alleviation of anxiety from ‘out‐of‐favor’ assets. The framework is applied to the development of a knowledge‐based portfolio system for constructing an investor's preference‐oriented portfolio. In the procedure of the system for ?nding an optimal portfolio, the system uses an arti?cial intelligence method of a case‐based reasoning to obtain preference thresholds for an investor when the investor's past investment records are available. Experimental results show that the framework contributes signi?cantly to the construction of a better portfolio from the perspective of an investor's bene?t/cost ratio than that produced by the existing portfolio models. Copyright © 2004 John Wiley & Sons, Ltd.     

Information Diversity and Market Behavior

The paper addresses two major issues raised by information diversity in a speculative market. First, we analyze what property of an investor's information leads to an expected speculative profit and show that independence is more important than accuracy. Second, we consider whether the market price must become fully efficient, in the sense that every investor's information is accurately discounted, when traders use it rationally as an information source. We prove that for any information structure there is a unique equilibrium weighting of investor beliefs at which the price is fully efficient and also every trader's expected profit is zero. Except for special structures, however, this equilibrium need not be attained in finite time.     

The Role of the Investment Horizon in Optimal Portfolio Sequencing (An Intuitive Demonstration in Discrete Time)

This paper examines the role played by the investor's investment horizon in the choice of optimal portfolios. A complete discrete-time, multiperiod, portfolio model is presented with a choice criterion that is consistent with the traditional utility approach but which is more amenable to a multiperiod environment. It is shown that investors should choose progressively less risky single-period portfolios as their investment horizons grow shorter, even if they do not become more risk averse. This result holds both in the presence and in the absence of a riskless asset. The results are consistent with empirical evidence and the financial planning practice of moving investors into progressively less risky portfolios as they grow older.     

Conditions Ensuring the Decomposition of Asset Demand for All Risk-Averse Investors

Abstract

The paper explores how the demand for a risky asset can be decomposed into an investment effect and a hedging effect by all risk-averse investors. This question has been shown to be complex when considered outside of the mean-variance framework. Dependence among returns on the risky assets is restricted to quadrant dependence and it is found that the demand for one risky asset can be decomposed into an investment component based on the risk premium offered by the asset and a hedging component used against the fluctuations in the return on the other risky asset. The paper also discusses how the class of quadrant-dependent distributions is related to that of two-fund separating distributions. This contribution opens up the search for broader distributional hypotheses suitable to asset demand models. Examples are discussed.     

The implied Sharpe ratio

In an incomplete market, including liquidly traded European options in an investment portfolio could potentially improve the expected terminal utility for a risk-averse investor. However, unlike the Sharpe ratio, which provides a concise measure of the relative investment attractiveness of different underlying risky assets, there is no such measure available to help investors choose among the different European options. We introduce a new concept—the implied Sharpe ratio—which allows investors to make such a comparison in an incomplete financial market. Specifically, when comparing various European options, it is the option with the highest implied Sharpe ratio that, if included in an investor's portfolio, will improve his expected utility the most. Through the method of Taylor series expansion of the state-dependent coefficients in a nonlinear partial differential equation, we also establish the behaviour of the implied Sharpe ratio with respect to an investor's risk-aversion parameter. In a series of numerical studies, we compare the investment attractiveness of different European options by studying their implied Sharpe ratio.     

Bond Covenants and Delegated Monitoring

This paper examines alternative contracting arrangements available to a firm seeking to finance an investment project. The authors consider the choice between loan contracts with covenants based on noisy indicators of the firm's financial health and loan contracts enforced by a monitoring specialist. In one interpretation, the specialist is a financial intermediary. The firm's choice is shown to depend upon the firm's credit rating, the accuracy of financial indicators of the firm's condition, the loss from premature liquidation of the firm's project, and the cost of monitoring.     

Asset allocation and investment horizon

Quarterly recommendations by national brokerage firms since the third quarter of 1989 provide an opportunity to compare different approaches to asset allocation. To follow a brokerage firm's recommendation every quarter is to practice tactical asset allocation. Both the length of the investor's decision horizon and brokerage commissions that are incurred when portfolio changes are made impact investment performance, and both contribute to the risk experienced by investors. Buy-and-hold and strategic asset allocation would have served investors better than tactical asset allocation during the first half of the 1990s.     

Lender Liability and Large Investors

We explore the optimal financial contract for a large investor with potential control over a firm's investment decisions. An optimal menu of claims resembles a U.S. version of lender liability doctrine—equitable subordination. This doctrine permits the court to subordinate a controlling investor's claim in bankruptcy, but only under well-specified conditions. It allows a firm to strike an efficient balance between: (i) inducing the large investor to monitor, and (ii) limiting the influence costs that arise when claimants can challenge existing contracts. We provide a partial rationale for a financial system in which powerful creditors do not hold blended debt and equity claims. Journal of Economic Literature Classification Numbers: G20, G33, K22.     

Optimal Asset-Liability Management for an Insurer Under Markov Regime Switching Jump-Diffusion Market

This paper considers an asset-liability management problem under a continuous time Markov regime-switching jump-diffusion market. We assume that the risky stock’s price is governed by a Markov regime-switching jump-diffusion process and the insurance claims follow a Markov regime-switching compound poisson process. Using the Markowitz mean-variance criterion, the objective is to minimize the variance of the insurer’s terminal wealth, given an expected terminal wealth. We get the optimal investment policy. At the same time, we also derive the mean-variance efficient frontier by using the Lagrange multiplier method and stochastic linear-quadratic control technique.     

DIVERSIFICATION AND SKEWNESS IN OPTION PORTFOLIOS

Skewness in returns is relevant to option investors. Because options possess positively skewed distributions, the traditional maxim of diversification, which can destroy positive skewness, is not necessarily consistent with investment objectives. The results indicate that the majority of skewness in option portfolios is diversified with a relatively small portfolio size, suggesting a strategy of antidiversification for option investors. Even though the investment performance of options is inferior to stocks on a risk-return basis, the data indicate the suitability of option portfolios in an environment where an investor's utility is measured by the return, risk, and skewness of the return distribution.     

Optimal Sequential Investment When Capital is Not Readily Reversible

When investment opportunities arrive one at a time and are reviewed sequentially, a corporation's optimal policy differs from a standard net present value rule if the corporation exercises control over an industry state variable and control is costly. The first condition presupposes a degree of market power for the firm; the second occurs if corporate investment decisions are imperfectly reversible. To address the problem of optimal investment in this context, a firm's investment decisions are modeled as a Markov reward process. The causes of economic irreversibility are discussed and general propositions concerning the optimal investment policy are derived. These propositions are then applied to the optimization of an exploration program by an oligopolistic firm (a price leader). Under particular demand and distributional assumptions, solutions for the optimal decision rule and the value of the exploration program are obtained and their properties examined.     

Investor preferences and portfolio selection: is diversification an appropriate strategy?

This paper analyzes the relationship between diversification and several distributional characteristics that have risk implications for stock returns. We develop a flexible three-parameter distribution to model the stock returns. Using data on the current 30 DJIA stocks, we show that an investor's strategy on diversification depends on the measures of risk for particular concerns. For example, investors who desire to increase positive skewness would hold a less diversified portfolio, while those who care more about extreme losses would hold a more diversified portfolio. Experimenting with a more general pool of stocks yields the same conclusions.     

Is socially responsible investment useful in Mexico? A multi-factor and ex-ante review

The present paper continues the firsts reviews made to socially responsible investment in Mexico. We extended these reviews by using a non-parametric multivariate equality test, along with a multi-factor market cap model, and a Monte Carlo simulation. Our results show that the IPCS index, the IPCcomp and the IPC have a statistically equal mean-variance performance, suggesting that this sort of investment style (SRI) is a good substitute of the broad market investment style in the long term. Among the causes of this finding is the fact that the IPCS and the IPCcomp indexes have almost the same large and small cap stock concentration and the IPC index (a large-cap one) is not as diversified and mean-variance efficient as the former.     

Risk-sensitive benchmarked asset management

This paper extends the risk-sensitive asset management theory developed by Bielecki and Pliska and by Kuroda and Nagai to the case where the investor's objective is to outperform an investment benchmark. The main result is a mutual fund theorem. Every investor following the same benchmark will take positions, in proportions dependent on his/her risk sensitivity coefficient, in two funds: the log-optimal portfolio and a second fund which adjusts for the correlation between the traded assets, the benchmark and the underlying valuation factors.     

Risk aversion and the yield of corporate debt

This paper develops a model to estimate the implied default probability of corporate bonds. The model explicitly considers the risk averse behavior of investors to provide a more precise framework for estimating the implied default probability. A Kalman filter method is used to estimate time-varying risk premium associated with the investor's risk aversion. The results of nonlinear regressions indicate that previous risk-neutrality models consistently overestimate the implied default rates of corporate bonds. The results also suggest that investors may have been adequately compensated for investment in risky bonds.     

Advertising in the mutual fund business: The role of judgmental heuristics in private investors' evaluation of risk and return

Effective advertising strategies are of growing importance in the mutual fund industry due to keen competition and changes in market structure. But the dominant variables in financial decision making, investor's perceived investment risk and expected return, have not yet been analysed in an advertising context, although these productrelated evaluations can be influenced by advertising and therefore serve as additional indicators of advertising effectiveness. In this study, the authors use a large-scale experimental study (n=499) to detect how risk-return assessments of private investors are influenced by specific elements of print ads. In this context, judgmental heuristics used systematically by private investors play a crucial role.     

Search for information and portfolio selection

The paper examines the problem of how to allocate scarce resources between increasing the investor's knowledge, that is reducing his uncertainty, and the actual investment—that is a kind of an ex ante decision before the final parameters of the securities are known. Our model provides answers to questions of how the search for knowledge affects portfolio selection, to what extent additional information can improve estimates of securities' statistical parameters and how the benefits and costs of additional search alter the investor's efficient mean-variance portfolio set.     

Voluntary disclosure of information when firms are uncertain of investor response

A firm may prefer not to disclose its private information if it is uncertain of investor response. In the setting under consideration, a firm needs to acquire capital from an investor. The investor can choose to invest in the firm, the risk free asset or in some alternative risky investment opportunity. It is shown that in a partial disclosure equilibrium, the firm discloses average information and withholds bad and good information. Disclosure of average information arises to attract the investor's capital away from the risk free asset.