The paper shows that the principal can enhance her control over the agent's human capital by acquiring the physical capital that is critical for him to create value. However, the enhancement in the control necessarily reduces his incentive to make human capital investment ex ante and to exert e�ort ex post. This trade-off between control and incentive thus decides the boundary of the firm. The paper also presents a rationale for M-form firms: centralized ownership of physical capital to facilitate coordination, and dispersed payoff rights to incentivize divisions.
