Bó, Pedro Dal (2005) “Cooperation under the Shadow of the Future: Experimental Evidence from Infinitely Repeated Games." American Economic Review, Volume 95, Number 5, December 2005 , pp. 1591-1604(14). ; brown.edu 提供的 [PDF] ; DOI: http://dx.doi.org/10.1257/000282805775014434 ;另見本站另一篇同作者在 2005AER 的文章；
==notes by yinung==
本篇以有限重覆賽局 PD game 為對照，比較無限重覆賽局之影響。
主要針對 equilibrium actions and equilibrium outcome ，而非 equilibrium strategies (可能要參考 Dale O. Stahl II (1991))
PD1 PD2 ============================= ============================= 合作 背叛 合作 背叛 合作 (65, 65) (10, 100) 合作 (75, 75) (10, 100) 背叛 (100,10) (35, 35) 背叛 (100,10) (45, 45) ============================= =============================
有限賽局的設計(Finitely Repeated Games)：
共有 1， 2，4 回合三種
子賽局均衡之推導，參見 Dale O. Stahl II (1991)
the set of subgame perfect equilibria can be calculated using the results in Dale O. Stahl II (1991).
…find strong evidence that the higher the probability of continuation, the higher the levels of cooperation.
針對 one-shot PD game; 合作率 9%； 無限重覆 （繼續機率=3/4) 合作率 38%。
…in the one-shot prisoner’s dilemma games studied here, the cooperation rate is 9 percent, for a probability of continuation of 3/4, it is 38 percent.
在有限重覆賽局中，也有終局效果 end-game effect，在最後一回合，合作率較低。
I find that the level of cooperation in the final round of the finitely repeated games is similar to the level of cooperation in one-shot games.
While there is an extensive literature on the theory of infinitely repeated games, empirical evidence on how “the shadow of the future" affects behavior is scarce and inconclusive. I simulate infinitely repeated prisoner’s dilemma games in the lab with a random continuation rule. The experimental design represents an improvement over the existing literature by including sessions with finite repeated games as controls and a large number of players per session (which allows for learning without contagion effects). I find that the shadow of the future matters not only by significantly reducing opportunistic behavior, but also because its impact closely follows theoretical predictions.
- 子賽局均衡之推導和 rate of cooperation outcome 的定義 (??)
Stahl, Dale O., II. “The Graph of Prisoner’s Dilemma Supergame Payoffs as a Function of the Discount Factor." Games and Economic Behavior, 1991, 3 (3), pp. 368 – 84.