On the Failures of Bonus Plans

A decision maker (DM) has some funds invested through two investment firms. She wishes to allocate additional funds according to the firms' earnings. The DM, on the one hand, tries to maximize the total expected earnings, while the firms, on the other hand, try to maximize the overall expected funds they manage. In this paper we prove that, for every market, the DM has an optimal bonus policy such that the firms are motivated to act according to the interests of the DM. On the other hand, we also prove that the only policy that is optimal in every market, is independent of the actions and earnings of the firms.