Knowledge that Transforms

In this paper, two possible premiums for delayed risks are presented and compared. It is shown that one of them possesses some properties usually considered desirable for ‘roulette gambles’ while the other definition does not meet the same requirements. Finally, the response of both premiums to increased wealth is discussed. The analysis of this problem sheds some light on the basic difference between delayed risks and roulette gambles.

This paper tests prediction of returns on stocks using a direct estimate of the minimum variance zero beta portfolio z. The composition of this portfolio is implicit in Black's paper on capital market equilibrium in the absence of riskless borrowing or lending. Portfolios of stocks drawn from the same industries are used to estimate z. The predictions of Black's equilibrium return equation are compared with those of cross-sectional regressions of return on risk.

This paper examines the ‘accuracy’ of information and its effect on social welfare. Information is defined to be more accurate than the existing information if individuals are willing to revise their subjective, homogeneous beliefs based on the new information. In a pure exchange economy where individuals may differ in endowments and tastes, it is shown that, for all utility functions satisfying risk aversion and non-satiation, the receipt of more accurate information does not increase social welfare (in terms of ex-ante Pareto-optimality) even when such information production is costless. This represents a more rigorous analysis on several issues that are not clear in the Marshall (1974) paper. Using the HARA class of utility functions, this paper also addresses the relationship between information and borrowing and lending, and the effect of information on the risk-free rate of interest.

In this paper, the portfolio and the liquidity planning problems are unified and analyzed in one model. Stochastic cash demands have a significant impact on both the composition of an individual's optimal portfolio and the pricing of capital assets in market equilibrium. The derived capital asset pricing model with cash demands and liquidation costs shows that both the market price of risk and the systematic risk of an asset are affected by the aggregate cash demands and liquidity risk. The modified model does not require that all investors hold an identical risky portfolio as implied by the Sharpe-Lintner-Mossin model. Furthermore, it provides a possible explanation for the noted discrepancies between the empirical evidence and the prediction of the traditional capital asset pricing model.

This paper attempts to clarify the apparent conflict between the recent contribution of Stiglitz and Smith (S-S) and the established Modigliani-Miller (M-M) leverage theorem. The two approaches differ in their treatment of asset creation. Whereas M-M restrict their discussion to a given set of competitive asset markets, S-S consider the addition of an extra asset to the original systems.

Although investors face multiperiod decision problems, there are conditions under which the results of the one-period two-parameter model apply period by period. In addition to the assumptions made in the development of the two-parameter model itself (a perfect capital market, investor risk aversion, and normal distributions of one-period portfolio returns), the critical assumption in a multiperiod context is that, for any t, returns on portfolio assets from t−1 to t are independent of stochastic elements of the state-of-the-world at time t that affect investor tastes for given levels of wealth to be obtained at t. One such element of the state-of-the-world is the nature of investment opportunities to be available at t. For example, if the level of expected returns on investment portfolios to be available at time t is uncertain at time t−1, and if the returns from t−1 to t on some investment assets are more strongly related to the level of expected returns at t than returns on other assets, then the former assets are better vehicles for hedging against the level of expected returns at t. This can affect the demands for assets and their prices in such a way that the simple results of the one-period two-parameter model do not hold. The empirical tests of this paper reveal no evidence of measurable relationships between the returns on portfolio assets from t−1 to t and the level of expected returns to be available at t. Indeed, in our opinion there is no reliable evidence that the level of expected returns changed during the 1953–1972 period.

Much controversy surrounds the use of the portfolio investment rules induced by maximizing the expected logarithm of terminal wealth (henceforth referred to as the MEL policy). It has been thought that the MEL policy is a good approximation to the optimal investment program when the utility of terminal wealth function is bounded and when the time horizon is long. However, I exhibit a class of bounded utility of terminal wealth functions for which the MEL policy is a very poor approximation to the optimal program. Hence, the wholesale use of the MEL policy as an approximation to the optimal program is unwarranted.

This paper examines stock market efficiency with respect to money supply data by testing (1) regression models of stock returns on monetary variables and (2) trading rules based on money supply data. The evidence indicates no meaningful lag in the effect of monetary policy on the stock market and that no profitable security trading rules using past values of the money supply exist. Therefore this evidence is consistent with the efficient market model. Current security returns incorporate all information contained in past money supply data and, in addition, appear to anticipate future changes in the money supply. A number of previous studies have concluded that lags exist and can be used in profitable trading rules. Analysis of these studies demonstrates that for a variety of reasons the evidence in these past studies does not sustain such conclusions.