Ambiguity and the bayesian paradigm

Itzhak Gilboa

Massimo Marinacci

pp. 385-439

in: Horacio Arló-Costa, Vincent F. Hendricks, Johan van Benthem (eds), Readings in formal epistemology, Berlin, Springer, 2016

Abstract

This is a survey of some of the recent decision-theoretic literature involving beliefs that cannot be quantified by a Bayesian prior. We discuss historical, philosophical, and axiomatic foundations of the Bayesian model, as well as of several alternative models recently proposed. The definition and comparison of ambiguity aversion and the updating of non-Bayesian beliefs are briefly discussed. Finally, several applications are mentioned to illustrate the way that ambiguity (or "Knightian uncertainty") can change the way we think about economic problems.