All-or-Nothing Monitoring
解释为何委托人即使能完美监督代理人除一项任务外的所有行动，仍可能只采用基于产出的激励合同，而不利用监督信息。
A principal can observe both the output and input of an agent who works at a job involving multiple tasks. We provide a simple theory that explains why it may be optimal for the principal to use only an output-based incentive contract, even though the principal can monitor the agent's actions perfectly in all but one task and knows exactly which action is optimal for each task.