Tractable (Simple) Contests

Tractable (Simple) Contests

Priel Levy, David Sarne, Yonatan Aumann

Proceedings of the Twenty-Seventh International Joint Conference on Artificial Intelligence
Main track. Pages 361-367. https://doi.org/10.24963/ijcai.2018/50

Much of the work on multi-agent contests is focused on determining the equilibrium behavior of contestants. This capability is essential for the principal for choosing the optimal parameters for the contest (e.g. prize amount). As it turns out, many contests exhibit not one, but many possible equilibria, hence precluding contest design optimization and contestants behavior prediction. In this paper we examine a variation of the classic contest that alleviates this problem by having contestants make the decisions sequentially rather than in parallel. We study this model in the setting of a simple contest, wherein contestants only choose whether or not to participate, while their performance level is exogenously set. We show that by switching to the revised mechanism the principal can not only force her most desired pure-strategies based equilibrium to emerge, but also, at times, end up with an equilibrium offering a greater expected profit. Further, we show that in the modified contest the optimal prize can be effectively computed. The theoretical analysis is complemented by comprehensive experiments with people over Amazon Mechanical Turk. Here, we find that the modified mechanism offers great benefit for the principal, both in terms of an increased over-participation in the contest (compared to theoretical expectations) and increased average profit.
Keywords:
Agent-based and Multi-agent Systems: Noncooperative Games
Agent-based and Multi-agent Systems: Economic Paradigms, Auctions and Market-Based Systems