In Ghirardato, Macheroni and MArcinaccri (GMM) propose a method for distinguishing between percieved ambiguity and the decision-maker's reaction to it. They study a general class of preferences which includes CEU and a-MEU and axiomatise a subclass of a-MEU preferences. We show that for Hurwicz...

This paper studies the impact of ambiguity in the best shot and weakest link models of public good provision. The models are ?rst analysed theoretically. Then we conduct experiments to study how ambiguity affects behaviour in these games. We test whether subjects? perception of ambiguity differs...

We report an experimental test of the influence of ambiguity on behaviour in a coordination game. We study the behaviour of subjects in the presence of ambiguity and attempt to determine whether they prefer to choose an ambiguity safe option. We fi?nd that this strategy, which is not played in...

The paper examines the effect of ambiguity on contests where multiple parties expend resources to win a prize. We develop a model where contenders perceive ambiguity about their opponents’ strategies and determine how perceptions of ambiguity and attitudes to ambiguity affect equilibrium...

In this paper we consider the effect of ambiguity on the private provision of public goods. Equilibrium is shown to exist and be unique. We examine how provision of the public good changes as the size of the population increases. We show that when there is uncertainty there may be less...

We examine the impact of ambiguity on economic behaviour. We present a relatively non-technical account of ambiguity and show how it may be applied in economics. Optimistic and pessimistic responses to ambiguity are formally modelled. We show that pessimism has the effect of increasing...

We report on an experiment in which subjects choose actions in strategic games with either strategic complements or substitutes against a granny, a game theorist or other subjects. The games are selected in order to test predictions on the comparative statics of equilibrium with respect to...

We provide an evolutionary foundation to evidence that in some situations humans maintain optimistic or pessimistic attitudes towards uncertainty and are ignorant to relevant aspects of the environment. Players in strategic games face Knightian uncertainty about opponents' actions and maximize...

We provide an evolutionary foundation to evidence that in some situations humans maintain either optimistic or pessimistic attitudes towards uncertainty and are ignorant to relevant aspects of the environment. Players in strategic games face Knightian uncertainty about opponents' actions and...