Dixit (1988) observed that the mathematical construct of "regulated Brownian motion" developed by Harrison (1985) had proved useful in economic models of decision-making under uncertainty. In a recent note he provided a number of methods for calculating expected discounted payoff functions based...

Two homogeneous stocks of physical capital are located in two different countries, separated by an "ocean." They are consumed by local residents, invested in a random production process yielding real returns, or transferred abroad. Under proportional transfer costs, trade, consumption, and...

When rates of return on bonds are computed over extremely short holding periods, the ex post cross-sectional relationship between realized return and risk is linear. It is therefore possible, at any time, to extrapolate the cross-sectional relationship to a zero risk level, and thus to determine...

When several investors with different risk aversions trade competitively in a capital market, the allocation of wealth fluctuates randomly among them and acts as a state variable against which each market participant will want to hedge. This hedging motive complicates the investors' portfolio...

Black and Scholes (1973) implied volatilities tend to be systematically related to the option's exercise price and time to expiration. Derman and Kani (1994), Dupire (1994), and Rubinstein (1994) attribute this behavior to the fact that the Black-Scholes constant volatility assumption is...

We develop a method that allows one to compute incomplete-market equilibria routinely for Markovian equilibria (when they exist). The main difficulty to be overcome arises from the set of state variables. There are, of course, exogenous state variables driving the economy but, in an incomplete...