We propose a new theory of systemic risk based on Knightian uncertainty (or "ambiguity"). We show that, due to uncertainty aversion, beliefs on future asset returns are endogenous, and bad news on one asset class induces investors to be more pessimistic about other asset classes as well. This...

We study a multidivisional firm where headquarters are exposed to moral hazard by division managers under uncertainty (or "ambiguity") aversion. We show the aggregation and linearity results of Holmström and Milgrom (1987) hold in an environment with IID ambiguity, as in Chen and Epstein...

We develop a theory of innovation waves, investor sentiment, and merger activity based on Knightian uncertainty. Uncertainty-averse investors are more optimistic on an innovation when they can make contemporaneous investments in multiple uncertain projects. Innovation waves occur when there is a...

We present a novel source of disagreement grounded in decision theory: ambiguity aversion. We show that ambiguity aversion generates endogenous disagreement between a firm's insider and outside shareholders, creating a new rationale for corporate governance systems. In our paper, optimal...

We explore the effects that optimism bias has on the demand for insurance. Our theory is based on a simple binomial model of the demand for insurance in which consumers make optimistically biased assessments concerning the likelihood of future outcomes. From this model, we derive an insurance...

This paper establishes a role for corporate governance regulation. An externality operating through executive compensation motivates regulation. Governance lowers agency costs, allowing firms to grant less incentive pay. When a firm increases governance and lowers incentive pay, other firms can...

We argue the earnings announcement premium is a measure of firm-specific uncertainty aversion. Our stylized model shows earnings announcements, as pure news events, are priced only if investors are uncertainty averse; further, the earnings announcement return is negatively correlated to future...

We explore demand for insurance in a setting where nonparticipation has been com-mon: health insurance. We present a stylized model of insurance demand in which consumers make optimistically-biased assessments about future health outcomes. The standard model would predict participation unless...

We consider the transitions among intragenerational and alternative intergenerational financing and liquidity risk-sharing mechanisms, in an Overlapping Generations model with endogenous levels of long-lived investments. The existence and characterization of a Self-Sustaining Mechanism, stable...

The critical role played by financial institutions in the recent financial crises has generated renewed interest on the corporate finance of the banking firm and the impact of the banking sector on the real economy. This paper introduces the special issue of the Review of Financial Studies...