Disclosure policy in contests with sabotage and group size uncertainty

In many contests, players are not aware of how many competitors they face. While existing studies examine how disclosing this number affects their productive effort, this paper is the first to consider its impact on destructive behavior. To do so, I theoretically and experimentally study how revealing the number of contestants affects both effort and sabotage compared to concealing this information. Further, I evaluate contestants’ productivity by comparing the resulting performances, which are shaped by the combination of the exerted effort and the received sabotage. I show that the overall performance can be higher under concealment, even though the disclosure policy does not affect average effort and sabotage levels. The experimental results largely confirm these theoretical predictions and demonstrate the significance of accounting for the effects of sabotage, as it induces performance differences between the group size disclosure policies. By concealing the number of contestants, a designer can mitigate the destructive effects of sabotage, without curbing the provision of productive effort.