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The folk theorem for repeated games with observation costs

  • Miyagawa, Eiichi
  • Miyahara, Yasuyuki
  • Sekiguchi, Tadashi

The folk theorem literature has been relaxing the assumption on how much players know about each other's past action. Here we consider a general model where players can "buy" precise information. Every period, each player decides whether to pay a cost to accurately observe the actions chosen by other players in the previous period. When a player does not pay the cost, he obtains only imperfect private signals. Observational decisions are unobservable to others. Known strategies such as trigger strategies do not work since they fail to motivate players to pay for information. This paper shows that the folk theorem holds for any level of observation costs. Unlike existing folk theorems with private monitoring, ours imposes virtually no restriction on the nature of costless imperfect signals. The theorem does not use explicit or costless communication, thereby having implications on antitrust laws that rely on evidence of explicit communication. The main message is that accurate observation alone, however costly, enables efficient cooperation in general repeated games.

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Article provided by Elsevier in its journal Journal of Economic Theory.

Volume (Year): 139 (2008)
Issue (Month): 1 (March)
Pages: 192-221

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Handle: RePEc:eee:jetheo:v:139:y:2008:i:1:p:192-221
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  1. Levine, David & Fudenberg, Drew, 1994. "Efficiency and Observability with Long-Run and Short-Run Players," Scholarly Articles 3203774, Harvard University Department of Economics.
  2. Piccione, Michele, 2002. "The Repeated Prisoner's Dilemma with Imperfect Private Monitoring," Journal of Economic Theory, Elsevier, vol. 102(1), pages 70-83, January.
  3. George J. Mailath & Stephen Morris, 2000. "Repeated Games with Almost-Public Monitoring," Econometric Society World Congress 2000 Contributed Papers 0661, Econometric Society.
  4. Yamamoto, Yuichi, 2007. "Efficiency results in N player games with imperfect private monitoring," Journal of Economic Theory, Elsevier, vol. 135(1), pages 382-413, July.
  5. Green, Edward J. & Porter, Robert H., 1982. "Noncooperative Collusion Under Imperfect Price Information," Working Papers 367, California Institute of Technology, Division of the Humanities and Social Sciences.
  6. Roy Radner & Roger Myerson & Eric Maskin, 1986. "An Example of a Repeated Partnership Game with Discounting and with Uniformly Inefficient Equilibria," Review of Economic Studies, Oxford University Press, vol. 53(1), pages 59-69.
  7. Sekiguchi, Tadashi, 1997. "Efficiency in Repeated Prisoner's Dilemma with Private Monitoring," Journal of Economic Theory, Elsevier, vol. 76(2), pages 345-361, October.
  8. Jeffrey C. Ely & Juuso Valimaki, 1999. "A Robust Folk Theorem for the Prisoner's Dilemma," Discussion Papers 1264, Northwestern University, Center for Mathematical Studies in Economics and Management Science.
  9. Jeffrey C. Ely & Johannes Hörner & Wojciech Olszewski, 2005. "Belief-Free Equilibria in Repeated Games," Econometrica, Econometric Society, vol. 73(2), pages 377-415, 03.
  10. Michihiro Kandori & Hitoshi Matsushima, 1998. "Private Observation, Communication and Collusion," Econometrica, Econometric Society, vol. 66(3), pages 627-652, May.
  11. Ben-Porath, Elchanan & Kahneman, Michael, 1996. "Communication in Repeated Games with Private Monitoring," Journal of Economic Theory, Elsevier, vol. 70(2), pages 281-297, August.
  12. Fudenberg, Drew & Maskin, Eric, 1986. "The Folk Theorem in Repeated Games with Discounting or with Incomplete Information," Econometrica, Econometric Society, vol. 54(3), pages 533-54, May.
  13. Michihiro Kandori & Hitoshi Matsushima, 1997. "Private observation and Communication and Collusion," Levine's Working Paper Archive 1256, David K. Levine.
  14. Abreu, Dilip & Pearce, David & Stacchetti, Ennio, 1990. "Toward a Theory of Discounted Repeated Games with Imperfect Monitoring," Econometrica, Econometric Society, vol. 58(5), pages 1041-63, September.
  15. Drew Fudenberg & David K. Levine & Eric Maskin, 1994. "The Folk Theorem with Imperfect Public Information," Levine's Working Paper Archive 2058, David K. Levine.
  16. Michihiro Kandori, 2001. "Randomization, Communication and Efficiency in Repeated Games with Imperfect Public Monitoring," CIRJE F-Series CIRJE-F-139, CIRJE, Faculty of Economics, University of Tokyo.
  17. Lehrer, Ehud, 1991. "Internal Correlation in Repeated Games," International Journal of Game Theory, Springer;Game Theory Society, vol. 19(4), pages 431-56.
  18. Matsushima, Hitoshi, 1991. "On the theory of repeated games with private information : Part II: revelation through communication," Economics Letters, Elsevier, vol. 35(3), pages 257-261, March.
  19. Ben-Porath, Elchanan & Kahneman, Michael, 2003. "Communication in repeated games with costly monitoring," Games and Economic Behavior, Elsevier, vol. 44(2), pages 227-250, August.
  20. Aoyagi, Masaki, 2002. "Collusion in Dynamic Bertrand Oligopoly with Correlated Private Signals and Communication," Journal of Economic Theory, Elsevier, vol. 102(1), pages 229-248, January.
  21. Hitoshi Matsushima, 2004. "Repeated Games with Private Monitoring: Two Players," Econometrica, Econometric Society, vol. 72(3), pages 823-852, 05.
  22. Olivier Compte, 1998. "Communication in Repeated Games with Imperfect Private Monitoring," Econometrica, Econometric Society, vol. 66(3), pages 597-626, May.
  23. Dilip Abreu & David Pearce & Ennio Stacchetti, 2010. "Towards a Theory of Discounted Repeated Games with Imperfect Monitoring," Levine's Working Paper Archive 199, David K. Levine.
  24. Lehrer, E, 1989. "Lower Equilibrium Payoffs in Two-Player Repeated Games with Non-observable Actions," International Journal of Game Theory, Springer;Game Theory Society, vol. 18(1), pages 57-89.
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