Awareness structures by Fagin and Halpern (1988) (FH) feature a syntactic awareness correspondence and accessibility relations modeling implicit knowledge. They are a flexible model of unawareness, and best interpreted from a outside modeler's perspective. Unawareness structures by Heifetz,...

We prove a no-speculative-trade theorem under unawareness for the infinite case. This generalizes the result for the finite case by Heifetz, Meier, and Schipper (2013).

We characterize the class of symmetric two-player games in which tit-for-tat cannot be beaten even by very sophisticated opponents in a repeated game. It turns out to be the class of exact potential games. More generally, there is a class of simple imitation rules that includes tit-for-tat but...

Heifetz, Meier and Schipper (2005) introduced a generalized state-space model that allows for non-trivial unawareness among several individuals and strong properties of knowledge. We show that this generalized state-space model arises naturally if states consist of maximally consistent sets of...

We analyze a symmetric n-firm Cournot oligopoly with a heterogeneous population of optimizers and imitators. Imitators mimic the output decision of the most successful firms of the previous round a la Vega-Redondo (1997). Optimizers play a myopic best response to the opponents' previous output....

Internet experiments are a new and convenient way for reaching a large subject pool. Yet, providing incentives to subjects can be a tricky design issue. One cost effective and simple method is the publication of a high score (as in computer games). We test whether a high score provides adequate...

In this paper we compare two different approaches to modeling unawareness: the object-based approach of Board and Chung (2007) and the subjective-state-space approach of Heifetz, Meier and Schipper (2006).

We use an experiment to explore how subjects learn to play against computers which are programmed to follow one of a number of standard learning algorithms. The learning theories are (unbeknown to subjects) a best response process, fictitious play, imitation, reinforcement learning, and a trial...

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...

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 ther subjects. The games are selected in order to test predictions on the comparative statics of equilibrium with respect to...