Games and Economic Behavior
Опубликовано на портале: 25-11-2004
David Myatt, Chris C. Wallace
Games and Economic Behavior.
2004.
Vol. 48.
No. 1.
P. 124-138.
Equilibrium selection in coordination games has generated a large literature. Kandori,
Mailath and Rob (1993) and Young (1993) studied dynamic models of aggregate behaviour
in which agents choose best responses to observations of population play. Crucially,
infrequent mistakes (`mutations`) allow agents to take actions contrary to current
trends and prevent initial configurations from determining long run play. An alternative
approach is offered here: Harsanyian trembles are added to agents` payoffs so that
with some probability it is optimal to act against the flow of play. The long run
distribution of population behaviour is characterised - modes correspond to stable
Bayesian Nash equilibria. Allowing the variance of payoff trembles to vanish, via
a purification process, a single equilibrium is played almost always in the long
run. Kandori et al and Young show that the number of contrarian actions required
to escape an equilibrium determines selection; here, the likelihood that such actions
are taken is of equal importance.

