A fundamental identification problem in program evaluation arises when idiosyncratic gains from participation and the treatment decision depend on each other. Imbens and Angrist (1994) were the first to exploit a monotonicity condition in order to identify an average treatment effect parameter...

Pricing pressure indices have recently been proposed as alternative screening devices for horizontal mergers involving differentiated products. We extend the concept of Upward Pricing Pressure (UPP) proposed by Farrell and Shapiro (2010) to two-sided markets. Examples of such markets are the...

We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry...

We study the effects of improvements in eBay’s rating mechanism on seller exit and continuing sellers’ behavior. Following a large sample of sellers over time, we exploit the fact that the rating mechanism was changed to reduce strategic bias in buyer rating. That improvement did not lead to...

Do some search engines produce better search results because their algorithm is better, or because they have access to more data from past searches? In the latter case, mandatory data sharing, a policy that is currently discussed, could trigger innovation and would benefit all users of search...

We use high frequency data on TV and radio advertising together with data on online sales for lottery tickets to measure the short run effects of advertising. We find them to be strong and to last for up to about 4 hours. They are the bigger the less time there is until the draw. We develop the...

In light of increasing health care expenditures, patient cost-sharing schemes have emerged as one of the main policy tools to reduce medical spending. We show that the effect of patient cost-sharing schemes on health care expenditures is not only determined by the economic incentives they...

We provide an explanation for the common finding that the effect of retirement on life satisfaction is negligible. For this we use subjective well-being measures for life and domains of life satisfaction that are available in the German Socio-Economic Panel (GSOEP) and show that the effect of...