Online advertising offers unprecedented opportunities for measurement. A host of new metrics, clicks being the leading example, have become widespread in advertising science. New data and experimentation platforms open the door for firms and researchers to measure true causal effects of...

Measuring the returns of advertising opportunities continues to be a challenge for many businesses. We design and run a field experiment in collaboration with Yelp across 18,294 firms in the restaurant industry to understand which types of businesses gain more from digital advertising. We...

COVID-19 vaccines are widely available in wealthy countries, yet many people remain unvaccinated. Understanding the effectiveness -- or lack thereof -- of popular vaccination campaign strategies is therefore critical. In this paper, we report results from two studies that tested strategies...

Third-party cookies and related 'offsite' tracking technologies are frequently used to share user data across applications in support of ad delivery. These data are viewed as highly valuable for online advertisers, but their usage faces increasing headwinds. In this paper, we quantify the...

Market definition is essential to merger analysis. Because no standard approach to market definition exists, opposing parties in antitrust cases often disagree about the extent of the market. These differences have been particularly relevant in the hospital industry, where the courts have denied...

Competition in many important industries centers on investment in intellectual property. Firms engage in dynamic, Schumpeterian competition for the market, through sequential winner-take-all races to produce drastic innovations, rather than through static price/output competition in the market....

We report a large-scale randomized controlled trial designed to assess whether the partisan cue of a provaccine message from Donald Trump would induce Americans to get COVID-19 vaccines. Our study involved presenting a 27-second advertisement to millions of U.S. YouTube users in October 2021....

Expenditures on prescription drugs are one of the fastest growing components of national health care spending, rising by almost three-fold between 1995 and 2007. Coinciding with this growth in prescription drug expenditures has been a rapid rise in direct-to-consumer advertising (DTCA), made...

Only recently introduced into the U.S. market, e-cigarettes have been aggressively promoted, and use is increasing rapidly among both adults and youths. At the heart of the regulatory debate are fundamental questions regarding whether e-cigarettes will draw cigarette smokers away from a...

It is often asserted that consumers are poorly informed about and inattentive to fuel economy, causing them to buy low-fuel economy vehicles despite their own best interest. This paper presents evidence on this assertion through two experiments providing fuel economy information to new vehicle...