What can be learned about marketing phenomena from descriptive, structural, and experimental empirical models? Is structure implicit in a descriptive empirical model? What is a "reduced-form model?" What is a natural experiment, and what can one infer from a study that uses experimental data?...

This paper describes regularities in the intraday spreads and prices quoted by dealers on the London Stock Exchange. It develops a measure of spread-related transaction costs, one that recognizes dealers' willingness to price trades within their quoted spreads. This measure of transaction costs...

Many provisions of the U.S. tax code affect corporate decisions to pay out or retain earnings. Most studies of these effects have examined the effects of dividend and capital gains taxes on payouts. Relatively few studies have considered the effects of corporate taxes on retentions. In the early...

This paper analyzes R&D policies when the returns to cost-reducing and demand-creating R&D are imperfectly appropriable and market structure is endogenous. Previous characterizations of appropriability are generalized to permit the possibility that own and rival R&D are imperfect substitutes. We...