Econometrica

Journal Of The Econometric Society

An International Society for the Advancement of Economic
Theory in its Relation to Statistics and Mathematics

Edited by: Guido W. Imbens • Print ISSN: 0012-9682 • Online ISSN: 1468-0262

Econometrica: Nov, 2023, Volume 91, Issue 6

Mixed Strategies in the Indefinitely Repeated Prisoner's Dilemma

https://doi.org/10.3982/ECTA17482
p. 2295-2331

Julian Romero, Yaroslav Rosokha

Identifying the strategies that are played is critical to understanding behavior in repeated games. This process is difficult because only choices (not strategies) are observable. Recently, a debate has emerged regarding whether subjects play mixed strategies in the indefinitely repeated prisoner's dilemma. We use an experimental approach to elicit mixed strategies from human subjects, thereby providing direct empirical evidence. We find that a majority of subjects use mixed strategies. However, the data also suggest subjects' strategies are becoming less mixed over time, and move toward three focal pure strategies: Tit For Tat, Grim Trigger, and Always Defect. We use the elicited strategies to provide an empirically‐relevant foundation for analyzing commonly used mixture model estimation procedures.


Full Content

Supplemental Material

Supplement to "Mixed Strategies in the Indefinitely Repeated Prisoner’s Dilemma"

Julian Romero and Yaroslav Rosokha

This online appendix contains material not found within the manuscript.

Supplement to "Mixed Strategies in the Indefinitely Repeated Prisoner’s Dilemma"

Julian Romero and Yaroslav Rosokha

This zip file contains the replication files for the manuscript.

Journal News

View