This paper studies an economy where agents trade using a shared language, so that they do not need to meet in person with goods physically present. Agents provide vague descriptions of proposed net trades, which we interpret as arising either from inherent limitations in what the agents can...

A decision maker (DM) is asked to make choices from a set of acts, which entail both risk and uncertainty in the sense of knight (1921). Extending Raiffa's (1961) argument I show that, provided the DM can choose acts objectively randomly (by flipping her own fair coin, for instance), provided...

Savage (1954) provided axioms on preferences over acts that were equivalent to the existence of an expected utility representation. We show that there is a continuum of other expected utility" representations in which for any act, the probability distribution over states depends on the...

Machina (2009, 2012) lists a number of situations where standard models of ambiguity aversion are unable to capture plausible features of ambiguity attitudes. Most of these problems arise in choice over prospects involving three or more outcomes. We show that the recursive non-expected utility...

Savage (1954) provides axioms on preferences over acts that are equivalent to the existence of a subjective expected utility representation. We show that there is a continuum of other "expected utility" representations in which for any act, the probability distribution over states depends on the...

Maximizing subjective expected utility is the classic model of decision-making under uncertainty. Savage (1954) provides axioms on preference over acts that are equivalent to the existence of a subjective expected utility representation, and further establishes that such a representation is...

This paper focuses on information acquisition and individual decision making in ambiguous situations and presents a novel experimental design which may help to tackle open questions from a fresh perspective. Instead of giving subjects the choice between risky and ambiguous Ellsberg urns, we let...

This paper reports experiments conducted to test whether ambiguity affects individual behaviour in games of strategic complements and strategic substitutes. We study subject behaviour in the presence of ambiguity in order to ascertain whether subjects' perception of ambiguity differs between a...

Observed individual behavior in the presence of ambiguity is characterized by insufficient responsiveness to changes in subjective likelihoods. Such likelihood insensitivity under ambiguity is integral to theoretical models and predictive of behavior in many important domains such as financial...