This paper examines dynamic pricing behavior in retail gasoline markets for 19 Canadian cities over 574 weeks.

In this article, I exploit a new station-level, twelve-hourly price dataset to examine the strong retail price cycles in the Toronto gasoline market. The cycles are visually similar to the theoretical Edgeworth Cycles of Maskin & Tirole [1988]: strongly asymmetric, tall, rapid, and highly synchronous across stations. I test a series of predictions made by the theory about how firm behaviors would differentially evolve over the path of a cycle. The evidence is consistent with the existence of Edgeworth Cycles and inconsistent with competing hypotheses. One finding is that smaller firms are more likely than larger firms to initiate rounds of price undercutting but the reverse is true for rounds of price increases. While the cycles are an interesting phenomenon for study in their own right, the evidence has important implications for understanding market power in both cycling and non-cycling gasoline markets.

We analyze the effect of Wal-Mart's entry into the grocery market using a unique store-level price panel data set. We use OLS and two IV specifications to estimate the effect of Wal-Mart's entry on competitors' prices of 24 grocery items across several categories. Wal-Mart's price advantage over competitors for these products averages approximately 10%. On average, competitors' response to entry by a Wal-Mart Supercenter is a price reduction of 1-1.2%, mostly due to smaller-scale competitors; the response of the "Big Three" supermarket chains (Albertson's, Safeway, and Kroger) is less than half that size. We confirm our results using a falsification exercise, in which we test for Wal-Mart's effect on prices of services that it does not provide, such as movie tickets and dry cleaning services.JEL Codes: L11, L13, L81

Strategic patenting is widely believed to raise the costs of innovating, especially in industries characterised by cumulative innovation. This paper studies the effects of strategic patenting on R&D, patenting and market value in the computer software industry. We focus on two key aspects: patent portfolio size, which affects bargaining power in patent disputes, and the fragmentation of patent rights (‘patent thickets’) which increases the transaction costs of enforcement. We develop a model that incorporates both effects, as well as knowledge spillovers. Using panel data for 121 firms covering the period 1980–99, we show that strategic patenting and spillovers affect innovation and market value of software firms, that there is a patent premium accounting for 20 per cent of the returns to R&D, and that software firms do not appear to be trapped in a prisoners' dilemma of ‘excessive patenting.’