Why Do Managers Diversify Their Firms? Agency Reconsidered
构建股东与管理者之间的契约模型，发现管理者进行多元化是为了获取私人利益而非降低风险，且多元化与管理者激励正相关。
We develop a contracting model between shareholders and managers in which managers diversify their firms for two reasons: to reduce idiosyncratic risk and to capture private benefits. We test the comparative static predictions of our model. In contrast to previous work, we find that diversification is positively related to managerial incentives. Further, the link between firm performance and managerial incentives is weaker for firms that experience changes in diversification than it is for firms that do not. Our findings suggest that managers diversify their firms in response to changes in private benefits rather than to reduce their exposure to risk.