One of the virtues of parameter preference models (presented in general form in Rubinstein [23]) is their empirical content. Applied models of financial theory rely heavily on the mean variance (MV) version of parameter preference. As spelled out in Samuelson [25], MV models are adequate with compact distributions of returns and when portfolio decisions are made frequently so that the risk parameter becomes sufficiently small.

Previous investigators have shown that the Sharpe measure of the performance of a managed portfolio may be flawed when the portfolio manager has market timing ability. Herein we develop the exact conditions under which the Sharpe measure will completely and correctly order market timers according to ability. The derived conditions are necessary, sufficient, and observable. We compare these derived conditions to empirical estimates of actual market conditions and find that, under typical market conditions, the practice of using quarterly portfolio return data will frequently result in a failure of the Sharpe measure to order timers according to ability. We show, however, that such failures can be greatly reduced by more frequent sampling of managed portfolio returns.

A number of futures contracts conveys to the short position various delivery options regarding the quality and exact timing of delivery. Moreover, the compensation to the long position is not solely determined by the market value of the delivered asset at the time of delivery. Sometimes, the long position can hedge this delivery risk by holding an appropriate portfolio of the underlying asset. It often has been stated that whenever the long position can form a dynamic hedge against the delivery risk, the delivery option has a zero value. This paper demonstrates the implication of such erroneous intuition to the pricing of options. It is shown that the root of the issue is the property of diffusion processes whereas, within a given time interval, a random variable either will never cross a given boundary or else, cross it an infinite number of times.

Equilibrium in the market for real assets requires that the price of those assets be bid up to reflect the tax shields they can offer to levered firms.Thus there must be an equality between the market values of real assets and the values of optimally levered firms.The standard measure of the advantage to leverage compares the values of levered and unlevered assets, and can be misleading and difficult to interpret.We show that a meaningful measure of the advantage to debt is the extra rate of return, net of a market premium for bankruptcy risk, earned by a levered firm relative to an otherwise-identical unlevered firm.We construct an option valuation model to calculate such a measure and present extensive simulation results.We use this model to compute optimal debt maturities, show how this approach can be used for capital budgeting, and discuss its implications for the comparison of bankruptcy costs versus tax shields.