In a world of certainty, the design of environmental policy is relatively straightforward, and boils down to maximizing the present value of the flow of social benefits minus costs. But the real world is one of considerable uncertainty -- over the physical and ecological impact of pollution,...

A simple model of equity pricing is developed to address two related questions. First, to what extent can unanticipated changes in such"fundamental" variables as profitability, real interest rates, inflation, and the variance of returns account for the observed behavior of the stockmarket?...

I discuss the antitrust suit brought by the U.S. Department of Justice against Visa and MasterCard in 1998. Banks that issue Visa cards are free to also issue MasterCard cards, and vice versa, and many banks issue the cards of both networks. However, both Visa and MasterCard had rules...

This paper examines the implications of the learning curve in a world of uncertainty. We consider a competitive firm whose costs decline with cumulative output. Because the price of the firm's output evolves stochastically, future production and cumulative output are unknown, and are contingent...

We study the effects of aggregate and idiosyncratic uncertainty on the entry of firms, total investment, and prices in a competitive industry with irreversible investment. We first use standard dynamic programming methods to determine firms' entry decisions, and we describe the resulting...

Under Section 201 of the 1974 Trade Act, a domestic industry can obtain temporary protection against imports by demonstrating before the International Trade Commission that it has been injured, and that imports have been the"substantial cause" of injury --i.e.,"a cause which is important and not...

Most explanations for the decline in share values over the past two decades have focused on the concurrent increase in inflation.This paper considers an alternative explanation: a substantial increase in the riskiness of capital investments. We show that the variance of firms' real gross...

We examine the role of network effects in the demand for pharmaceuticals at both the brand level and for a therapeutic class of drugs. These effects emerge when use of a drug by others conveys information about its efficacy and safety to patients and physicians. This can lead to herd behavior...

A recent literature suggests that because investment expenditures are irreversible and can be delayed, they may be highly sensitive to uncertainty. We briefly summarize the theory, stressing its empirical implications. We then use cross-section and time-series data for a set of developing and...

This paper addresses the impact on investment incentives of the network sharing arrangements mandated by the Telecommunications Act of 1996, with a focus on the implications of irreversible investment. Although the goal is to promote competition, the sharing rules now in place reduce incentives...