Model builders face ambiguity about the true data generating process. Consequently, they need to deal with ambiguity attitudes (inside uncertainty) and ambiguous financial reality (outside uncertainty) when developing and estimating financial models. We introduce a novel approach for...

This paper studies the pricing implications of the sole ambiguity aversion, in a Lucas’ tree economy where asset returns are ambiguous. Abstracting from a specific functional form, we disentangle the model-specific effect from the effect of ambiguity aversion. In addition, we allow the...

Between August and September 2012, the American political magazine, Foreign Policy asked a total of 62 well-known US economists what they saw as the main reason for the slow recovery of the labor market. The most common response was "uncertainty" (31 percent). But what exactly does this term...

Ambiguity aversion in dynamic models is motivated by the presence of unknown time-varying features, which agents do not understand and cannot theorize about. We analyze the consequences of this assumption for economic agents and model builders, who typically need to estimate a model, e.g., to...

We propose and axiomatize a new model of preferences that achieves a separation between ambiguity, identified as a characteristic of the decision maker's subjective information, and ambiguity attitude, a characteristic of the decision maker's tastes.

This paper axiomatizes an intertemporal version of the Smooth Ambiguity decision model developed in Klibanoff, Marinacci, and Mukerji (2005). A key feature of the model is that it achieves a separation between ambiguity, identified as a characteristic of the decision maker's subjective beliefs,...

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...

Which issues are discussed by candidates in an election campaign? Why are some issues never discussed? Model tractability is lost quickly when dealing with these questions, partly because of the multidimensional voting inherent in models of multiple issues. Our model features two candidates for...

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...