Estimating Beta

This paper presents evidence that Ordinary Least Squares estimators of beta coefficients of major firms and portfolios are highly sensitive to observations of extremes in market index returns. This sensitivity is rooted in the inconsistency of the quadratic loss function in financial theory. By introducing considerations of risk aversion into the estimation procedure using alternative estimators derived from Gini measures of variability one can overcome this lack of robustness and improve the reliability of the results.     

Accounting data and asset valuation: Theory

Firms and divisions which are not traded on organized exchanges are often valued without the benefit of market data. Accounting data is used instead. One suggested approach is to use accounting beta as a proxy for market return beta. In the context of the Arbitrage Pricing Theory, we provide a theoretical justification for such a procedure. Our results provide a set of sufficient conditions so that return betas and accounting betas are equal. Our results also suggest a general methodology for evaluating projects and untraded firms using accounting data. The method underlying the derivation here is very general and can be applied in deriving testable restrictions between fundamentals, broader in context than that of accounting variables.     

Small firm effect: The case for banks

This article contributes to the small firm effect literature by examining weekly returns on common stocks of 73 banks for the 19-year period from 1969 to 1987. It differs from previous research in this area in both the analytical tool employed and the sampled firms. The findings suggest that the small firm effect is strong, is persist over long investment periods, and is monotonically increasing with the increase in firms' size.     

Tests of the efficiency of the U.S. rights offering market: An option pricing approach

The efficiency of the U.S. market for stock purchase rights is empirically analyzed in an options framework, in which prices of rights, given the prices of underlying stock, are examined with regard to the possibilities of actually earning above-normal profits, considering the risk taken. Two neutral hedging tests for market efficiency, along with a simple buy-and-exercise trading strategy, are applied to daily traded rights data. Results from ex-post hedging tests suggest that the trading strategy based on the rights valuation model is able to differentiate between overpriced and underpriced rights so as to generate substantial book profits. The positive ex-ante hedge return, found to exist empirically, is completely eliminated once transaction costs are introduced, lending support for the efficient U.S. rights offering market on an after-transaction cost basis.     

Optimal growth portfolios reconciling theory and practice

Modern portfolio theory dictates diversification among assets that are not perfectly correlated (that is, asset diversification). Professional investors, on the other hand, contend that one can simply diversify across time (that is, time diversification). The controversy of time diversification versus asset diversification is examined in this article by empirically analyzing the optimum investment strategies for a myopic utility function (the extreme case that supports across asset diversification) under varying degrees of relative risk aversion. While Merton and Samuelson (1974) and Samuelson (1990) show that with a myopic utility function the investment diversification strategy does not change with an increase in the investment horizon, the recommendation of professional investors is also found to hold since for a wide range of relative risk-aversion measures, the optimum portfolio is shown to consist almost entirely of equities.     

Seasonality in outliers of daily stock returns: A tail that wags the dog?

We document significant intra-year seasonality in outliers of S&P500 daily rates of return. Controlling for outliers in dummy regressions reveals that both the January and Monday effects turn from insignificant to highly significant. Mean daily return on January doubles and becomes significantly higher than all other months of the year, and Monday's mean return turns significantly positive and higher than other days of the week. The recently documented Halloween effect turns significant only after controlling for outliers as June, August, and September turn out to be months with remarkably low rates of returns. Being random, outliers cannot serve as instrumental variables for designing trading rules, yet, their impact on options pricing through the increase in volatility, may be applied for profitable options strategies.     

Expectations,information, and migration: the case of the West Bank and Gaza

"This study evaluates the determinants of Palestinian migration from the West Bank and Gaza. Data are employed for the post-1967 period of Israeli rule to specify and test competing models as well as the strucure of expectations in the migration decision. Results of the analysis support a simple static expectation formulation, as is consistent with much of the short-term, low mobility cost migration between the West Bank and Jordan. Findings further point to the importance of various Israeli-Palestinian economic and political economic interactions in the determination of this controversial movement of population, including those associated with employment opportunity for Palestinian labour in Israel, elements of Israeli West Bank settlement policy and changes in local standard of living. Various policy implications of the research are indicated."     

Financial opening, deposit insurance, and risk in a model of banking competition

We study the impact of competition on banks’ risk-taking behavior under different assumptions about deposit insurance and the dissemination of information. While financial opening increases banks’ riskiness, a risk-based deposit insurance or, alternatively, the public disclosure of financial information, are likely to mitigate this effect. Moreover, the limiting cases of uninsured but fully informed depositors, and risk-based full deposit insurance, yield the same equilibrium risk level. Although the welfare consequences of increased competition depend on its impact on risk, financial opening unambiguously improves welfare as we approach the limiting cases.     

Economic Analysis at the Federal Communications Commission

This article reviews some of the major economic issues faced by the FCC in thelast year. It focuses on the application of new analytic techniques at the FCC, andidentifies several areas in which further academic research would be valuable to theFCC.Currently serving as FCC Chief Economist