英国财政研究所（IFS）：多任务,两部分合同和集中医生任务的应用（英文版）

The optimal design of incentive contracts critically depends on whether the tasks performed by agents are complementary or substitutable, yet empirical evidence on this remains limited. This paper develops a novel empirical strategy to identify complementarities and substitutabilities in tasks, even in the absence of contract variation across agents, provided the incentive contract is piecewise linear. We apply this method to data on the management of chronic diseases by UK family physicians