Many economic decisions can be described as an option exercise or optimal stopping problem under uncertainty. Motivated by experimental evidence such as the Ellsberg Paradox, we follow Knight (1921) and distinguish risk from uncertainty. To afford this distinction, we adopt the multiple-priors utility model. We show that the impact of ambiguity on the option exercise decision depends on the rel...

We study the optimal insurance demand of a riskand ambiguity-averse consumer if contract nonperformance risk is perceived as ambiguous. We find that the consumer’s optimal insurance demand is lower compared to a situation without ambiguity and that his degree of ambiguity aversion is negatively associated with the optimal level of coverage. We also determine sufficient conditions for biased bel...

In this paper I use the smooth ambiguity model developed by Klibanoff, Marinacci, and Mukerji (2005) to define the concepts of ambiguity and uncertainty premia in a way analogous to what Pratt (1964) did in the risk theory literature. I show that those concepts may be useful to quantify the effect ambiguity has on the welfare of economic agents. I also provide local approximations of these prem...

This paper presents a positive theory about the contractual form of procurement contracts under cost uncertainty. While the cost of manufacture is uncertain it can be controlled, to an extent depending on the effort exerted by the agent. The effort exerted by the agent is not contractible but causes disutility to the agent. Hence, the amount of effort exerted depends on the power of incentives ...

In a equilibrium model with uncertainty averse consumers, we prove that more ambiguity aversion implies less trade. The reduction in trade caused by ambiguity aversion can be as severe as to lead to no-trade, even in the Choquet Expected Utility (CEU) or Maximin Expected Utility (MEU) models. Our results do not assume that consumers have constant endowments, as usual in the literature, but only...

It is widely thought that incomes risks can be shared by trading in financial assets. But financial assets typically carry some risk idiosyncratic to them, hence, disposing incomes risk using financial assets will involve buying into the inherent idiosyncratic risk. However, standard theory argues that diversification would reduce the inconvenience of idiosyncratic risk to arbitrarily low level...

This article uses the recent Delaware Chancery Court case ofHexion v. Huntsman as a template for motivating thoughts about how contract law should interpret contractual conditions in general--and "material adverse event"provisions in particular-within environments of extreme ambiguity (as opposed to risk). Although ambiguity and aversion thereto bear some facial similarities to risk and risk av...

Economic approaches to precaution: a critical presentation. The precautionary principle is well known nowadays. But does it have an economic foundation? We present two theories of precaution. The first is based on the standard model of expected utility with a Bayesian belief revision. The second is based on ambiguity aversion. We discuss the advantages as well as the weaknesses of these two app...