Abstract
We consider a game in which the action set of each player is uncountable, and show that, from weak assumptions on the common prior, any mixed strategy has an approximately equivalent pure strategy. The assumption of this result can be further weakened if we consider the purification of a Nash equilibrium. Combined with the existence theorem for a Nash equilibrium, we derive an existence theorem for a pure strategy approximated Nash equilibrium under sufficiently weak assumptions. All of the pure strategies we derive in this paper can take a finite number of possible actions.
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We are grateful to Toru Maruyama, Shinsuke Nakamura, Takako Fujiwara-Greve, and Toru Hokari for their helpful comments and suggestions. We also thank the anonymous reviewers for their helpful comments and suggestions on this paper. This work was supported by JSPS KAKENHI Grant number JP21K01403.
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Hosoya, Y., Yu, C. On the approximate purification of mixed strategies in games with infinite action sets. Econ Theory Bull 10, 69–93 (2022). https://doi.org/10.1007/s40505-022-00219-1
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DOI: https://doi.org/10.1007/s40505-022-00219-1