We investigate what it means for one act to be more ambiguous than another. The question is evidently analogous to asking what makes one prospect riskier than another, but beliefs are neither objective nor representable by a unique probability. Our starting point is an abstract class of...

We examine a variety of preference-based definitions of ambiguous events in the context of the smooth ambiguity model.  We first consider the definition proposed in Klibanoff, Marinacci, and Mukerji (2005) based on the classic Ellsberg two-urn paradox (Ellsberg (1961)), and show that it...

We define a behavioral concept of relevance in the context of decision making under uncertainty.  We argue that this concept provides a sensible answer to the question "What probabilistic environments do an individuals' preferences reveal as mattering to her decisions?" under a symmetry...

This introductory article reviews the main themes relating to the development of new knowledge-based economies. After placing their emergence in historical perspective and proposing a theoretical framework which distinguishes knowledge from information, the authors characterize the specific...

Criminals who wear gang colors are acting in a surprisingly brazen way which must increase the probability of being caught and punished by the police.  In our model this brazen behavior is a solution to an enforcement problem.  The central idea is that less able criminals see lower gains from...

We axiomatize preferences that can be represented by a monotonic aggregation of subjective expected utilities generated by a utility function and some set of i.i.d. probability measures over a product state space, S1. For such preferences, we define relevant measures, show that they are treated...

Are foundations of models of ambiguity-sensitive preferences too flawed to be usefully applied to economic models?  Al-Najjar and Weinstein (2009) say such is indeed the case.  In this paper, first, we point out that many of the key arguments by Al-Najjar and Weinstein do not apply to quite a...

Epstein (2009) describes three Ellsberg-style thought experiments and argues that they pose difficulties for the smooth ambiguity model of decision making under uncertainty developed by Klibanoff, Marinacci and Mukerji (2005).  We revisit these thought exeperiments and find, to the contrary,...

We propose and axiomatize a model of preferences over acts such that the decision maker evaluates acts according to the expectation (over a set of probability measures) of an increasing transformation of an act`s expected utility. This expectation is calculated using a subjective probability...

This paper provides a positive theory about the contractual form of procurement contracts under cost uncertainty. However, while the cost of manufacture is uncertain it can be reduced by an amount depending on the extent of effort exerted by the agent. The effort exerted by the agent is not...