We present a non-technical account of ambiguity in strategic games and show how it may be applied to economics and social sciences. Optimistic and pessimistic responses to ambiguity are formally modelled. We show that pessimism has the effect of increasing (decreasing) equilibrium prices under...

A decision-maker is said to have an ambiguous belief if it is not precise enough to be represented by a single probability distribution. The pervasive assumption in game theoretic models in economics is that players' beliefs are unambiguous. This paper argues, drawing on examples from economics...

The endogeneity of equilibrium strategies makes modelling uncertainty about the behaviour of other economic players difficult. Recent developments in decision and game theory offer an opportunity to include strategic uncertainty as an explanatory variable in economic analysis. This paper...

This paper introduces E-capacities as a representation of beliefs which incorporates objective information about the probability of events. It can be shown that the Choquet integral of an E-capacity is the Ellsberg representation. The paper further explores properties of this representation of...

We examine the effect of introducing Knightian uncertainty into a simple model of public good provision. We find that uncertainty may reduce the free-rider problem if utility is concave in public goods or there are decreasing returns to scale in the production of public goods. It is possible...