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...

The theory of incomplete contracting is rival to that of complete contracting as a frame of reference to understand contractual relationships. Both approaches rest upon diametrically opposed postulates and lead to very different policy conclusions. From a theoretical viewpoint, scrutiny of the...

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...

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...

As firms have more assets in place, more of management's limited attention is focused on managing assets in place rather than developing new growth options. Consequently, as firms grow older, they have fewer growth options and a lower ability to generate new growth options. This simple theory...

Many basic economic theories with perfectly functioning markets do not predict the existence of the vast number of microenterprises readily observed across the world. We put forward a model that illuminates why financial and managerial capital constraints may impede experimentation, and thus...

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...

Measuring the private returns to R&D requires knowledge of its private depreciation or obsolescence rate, which is inherently variable and responds to competitive pressure. Nevertheless, most of the previous literature has used a constant depreciation rate to construct R&D capital stocks and...

Recently, the relative demand for skilled labor has increased dramatically. We investigate one of the causes, skill-biased technical change. Advances in information technology (IT) are among the most powerful forces bearing on the economy. Employers who use IT often make complementary...