Online interactions are frequently governed by reputation systems that allow users to evaluate each other after an interaction. Effective reputation systems can increase trust and may improve efficiency in market settings. In recent years, however, fake reviews have become increasingly...

Exploiting the natural experiment of the German reunification, we examine how consumers adapt to a new environment in their macroeconomic forecasting. We document that East Germans expect higher inflation and make larger forecast errors than West Germans even decades after reunification....

We investigate overlapping contests in multi-divisional organizations in which an individual's effort simultaneously determines the outcome of several contests on different hierarchical levels. We show that individuals in larger units are disadvantaged in the grand (organization-wide) contest...

Contests are well-established mechanisms for political lobbying, innovation, rentseeking, incentivizing workers, and advancing R&D. A well-known theoretical result in the contest literature is that greater heterogeneity decreases investments of contestants because of the "discouragement effect."...

We develop a general framework to study contests, containing the well-known models of Tullock (1980) and Lazear & Rosen (1981) as special cases. The contest outcome depends on players' effort and skill, the latter being subject to symmetric uncertainty. The model is tractable, because a...

Many situations in the social and economic life are characterized by rivalry and conflict between two or more competing groups. Warfare, socio-political conflicts, political elections, lobbying, and R&D competitions are all examples of inter-group conflicts in which groups spend scarce and...

Volunteering is a widespread allocation mechanism at the workplace and emerges naturally in open-source software development, the generation of online knowledge platforms, and to some extent in "agile" work environments. Using a field experiment with 8 treatments and close to 2,800 workers on an...

I use game-theoretical models to compare a sender's expected payoff under two methods of wielding influence under incomplete information: offering rewards or threatening punishments. Attempts to influence another's behaviour can have the perverse effect of actually encouraging the behaviour that...

Many papers have reported behavioral biases in belief formation that come on top of standard game-theoretic reasoning. We show that the processes involved depend on the way participants reason about their beliefs. When they think about what everybody else or another "unspeci fied" individual is...

We investigate experimentally on eBay how sellers set prices in "Buy-It-Now" (BIN) auctions. We find that the eBay format leads to prices substantially below those expected in second-price auctions. Moreover, our results reveal that the information available on eBay about buyer experience and...