We document that the risks and pre-fee returns of broad hedge fund indices can be accurately matched with simple equity index put writing strategies, which provide monthly liquidity and complete transparency over their state-contingent payoff profiles. This nonlinear risk exposure combines with...

We introduce and analyze a model in which agents observe sequences of signals about the state of the world, some of which are ambiguous and open to interpretation. Instead of using Bayes' rule on the whole sequence, our decision makers use Bayes' rule in an iterative way: first to interpret each...

We review and extend the economic analysis of risk and uncertainty as it relates to behavior mitigating health shocks. We summarize some central aspects of the vast positive and normative literature on the role of various forms of insurance that attempt to smooth consumption, which can be uneven...

We investigate the importance of ambiguity, or Knightian uncertainty, in executives' decisions about when to exercise stock options. We develop an empirical estimate of ambiguity and include it in regression models alongside the more traditional measure of risk, equity volatility. We show that...

This article develops two points. First, insurance against the risk of legal change is largely unavailable, primarily because of the correlated nature of the losses that legal change generates. Second, given the absence of insurance against legal change, it is generally desirable for legal...

Uncertainty is intrinsic to climate change: we know that the climate is changing, but not precisely how fast or in what ways. Nor do we understand fully the social and economic consequences of these changes, or the options that will be available for reducing climate change. Furthermore the...

Technological progress is typically a result of trial-and-error research by competing firms. While some research paths lead to the innovation sought, others result in dead ends. Because firms benefit from their competitors working in the wrong direction, they do not reveal their dead-end...

We present a model in which managers are risk-averse and firms compete for scarce managerial talent ("alpha"). When managers are not mobile across firms, firms provide efficient compensation, which allows for learning about managerial talent and for insurance of low-quality managers. When...

Time-inconsistency of no-bailout policies can create incentives for banks to take excessive risks and generate endogenous crises when the government cannot commit. However, at the outbreak of financial problems, usually the government is uncertain about their nature, and hence it may delay...

We test the relation between ambiguity aversion and five household portfolio choice puzzles: non- participation, low allocations to equity, home-bias, own-company stock ownership, and portfolio under- diversification. In a representative U.S. household survey, we measure ambiguity aversion using...