Robust Incentives for Teams*
This paper considers team incentive schemes that are robust to nonquantifiable uncertainty about the game played by the agents. A principal designs a contract for a team of agents, each taking an unobservable action that jointly determine a stochastic contractible outcome. The game is common knowledge among the agents, but the principal only knows some of the available action profiles. Realizing that the game may be bigger than he thinks, the principal evaluates contracts based on their guaranteed performance across all games consistent with his knowledge. All parties are risk neutral and the agents are protected by limited liability. A contract is said to align the agents' interests if each agent's compensation covaries positively and linearly with the other agents' compensation. It is shown that contracts that fail to do so are dominated by those that do, both in terms of the surplus guarantee under budget balance, and in terms of the principal's profit guarantee when he is the residual claimant. It thus suffices to base compensation on a one dimensional aggregate even if richer outcome measures are available. The best guarantee for either objective is achieved by a contract linear in the monetary value of the outcome. This provides a foundation for practices such as team based pay and profit sharing in partnership.