Correlated Equilibrium and Private Monitoring
by
Jeff Ely
Northwestern University

In repeated games, simple strategies such as Grim Trigger, while strict equilibria when monitoring is perfect, can fail to be even approximate Nash equilibria when monitoring is private, yet arbitrarily close to perfect. That is, they fail to be robust to private monitoring. In this paper, it is shown that for a class of repeated Prisoners' Dilemma games these strategies, when viewed as (degenerate) correlated equilibria are robust. In particular, even when monitoring is private and conditionally independent, as the signalling noise goes to zero, there is a sequence of correlated equilibria converging to the Grim Trigger strategies. The correlation device uses an information structure akin to that of Rubinstein's e-mail game.

http://www.kellogg.nwu.edu/research/math/papers/1265.pdf

Date received: June 12, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cafi-56.