I develop an analytically tractable model that integrates the risk-shifting problem between bondholders and shareholders with the moral-hazard problem between shareholders and the manager. An optimal contract binds shareholders and the manager, and this contract’s flexibility allows shareholders to relax the manager’s incentive constraint following a “good” profitability shock. Thus, the optimal contract amplifies the upside and thereby increases shareholder appetite for risk shifting. Whereas some empirical studies find a positive relation between risk shifting and leverage, others find a negative relation. This model predicts a non-monotonic relation between risk shifting and leverage and can reconcile these contradictory empirical findings.

We study a continuous‐time contracting problem under hidden action, where the principal has ambiguous beliefs about the project cash flows. The principal designs a robust contract that maximizes his utility under the worst‐case scenario subject to the agent's incentive and participation constraints. Robustness generates endogenous belief heterogeneity and induces a tradeoff between incentives and ambiguity sharing so that the incentive constraint does not always bind. We implement the optimal contract by cash reserves, debt, and equity. In addition to receiving ordinary dividends when cash reserves reach a threshold, outside equity holders also receive special dividends or inject cash in the cash reserves to hedge against model uncertainty and smooth dividends. The equity premium and the credit yield spread generated by ambiguity aversion are state dependent and high for distressed firms with low cash reserves.

ABSTRACT We examine executive compensation in a general equilibrium model with dynamic moral hazard, where executives' outside options are endogenously determined by equilibrium market compensation. Firms provide incentives through compensation packages featuring deferred payments as “carrots” and termination as “sticks.” Crucially, the effectiveness of termination as an incentive device is undermined by the outside options available to executives. As individual firms fail to internalize the effect of their compensation design on these endogenous outside options, the equilibrium is generally inefficient. Compared to shareholder‐value‐maximizing compensation packages, executives are paid too much, too soon, and keep their jobs for too long.

We demonstrate that investment income taxes incentivize capital allocation to the ecofriendly green sector away from the non-ecofriendly brown sector in a stylized economy. This tax reduces the arrival intensity of climate disasters, delivers the socially optimal allocation, and can be jointly implemented with a carbon tax, expanding policymakers’ toolkit to reduce climate disasters. Extending the model with heterogeneous investors, we show that investment income taxes can obtain support from a political majority and thereby relax political constraints faced by a carbon tax alone.

Unlike labor income, human capital is inseparable from individuals and does not completely accrue to creditors. Therefore, human capital investment is more resilient to “debt overhang” than labor supply. We develop a dynamic model displaying this difference. We find that while both labor supply and human capital investment are hump-shaped in household indebtedness, human capital investment declines less aggressively as indebtedness builds up. Importantly, because human capital is only valuable when households expect to supply labor, the greater reduction in labor supply due to debt overhang back-propagates into ex-ante human capital investment. We provide empirical support for the model.