# When is tit-for-tat unbeatable?

Peter Duersch (), Jörg Oechssler and Burkhard Schipper ()
Authors registered in the RePEc Author Service: Peter Dürsch

International Journal of Game Theory, 2014, vol. 43, issue 1, 25-36

Abstract: 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 also imitate-the-best and imitate-if-better. Every decision rule in this class is essentially unbeatable in exact potential games. Our results apply to many interesting games including all symmetric 2 $$\times$$ 2 games, and standard examples of Cournot duopoly, price competition, public goods games, common pool resource games, and minimum effort coordination games. Copyright Springer-Verlag Berlin Heidelberg 2014

Keywords: Imitation; Tit-for-tat; Decision rules; Learning; Exact potential games; Symmetric games; Repeated games; Relative payoffs; Zero-sum games; C72; C73; D43 (search for similar items in EconPapers)
Date: 2014
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http://hdl.handle.net/10.1007/s00182-013-0370-1 (text/html)

Related works:
Working Paper: When is Tit-For-Tat unbeatable? (2013)
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