Internet advertising has been the fastest growing advertising channel in recent years with paid search ads comprising the bulk of this revenue. We present results from a series of large scale field experiments done at eBay that were designed to measure the causal effectiveness of paid search...

We introduce a simple and robust approach to answering two key questions in empirical auction analysis: discriminating between models of entry and quantifying the revenue gains from improving auction design. The approach builds on Bulow and Klemperer (1996), connecting their theoretical results...

This paper reviews the literature devoted to studying markets for health care services and health insurance. There has been tremendous growth and progress in this field. A tremendous amount of new research has been done in this area over the last 10 years. In addition, there has been increasing...

Regulating bidder participation in auctions can potentially increase efficiency compared to standard auction formats with free entry. We show that the relative performance of two such mechanisms, a standard first-price auction with free entry and an entry rights auction, depends...

This paper brings new evidence from the privatized social security system in Mexico, offering insight into investment behavior and the efficacy of government "nudges" in the context of profit maximizing firms. We use administrative data from the social security system surrounding the government...

This paper examines how advertising impacts competition and equilibrium prices in the context of a privatized pension market. We use detailed administrative data on fund manager choices and worker characteristics at the inception of Mexico's privatized social security system, where fund managers...