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...

In many business transactions, in labor-management relations, in internationalconflicts, and welfare state reforms bargainers hold strong entitlements that are oftengenerated by claims that are not feasible any more. These entitlements seem to considerablyshape negotiation behavior. By using the...

This paper studies the relevance of social interactions among the unemployed. Identification is based on a salient and selective extension of the potential duration of unemployment benefits. If social interactions are important, this policy change affects entitled individuals not only directly,...

These notes review two simple heterogeneous agent models in economics and finance. The first is a cobweb model with rational versus naive agents introduced in Brock and Hommes (1997). The second is an asset pricing model with fundamentalists versus technical traders introduced in Brock and...

A fundamental question in social sciences is how trust emerges. We provide an answer which relies on the formation of social and economic relationships. We argue that behind trust lies the fact that individuals invest in connections taking into account the potential externalities networks...