Difficulty of Cooperation in Iterated Multi-Prisoner's Dilemma Situation-experimental Evidence

It is popular that two players face with each other repeatedly in different phases [1]. Workers usually have relationship with their colleagues not only at work but also privately. Governments make negotiations on agricultural trade in addition to industrial trade. A hotel chain competes with the rival in various areas. Do these situations facilitate cooperation? What kind of decision makings should players offer to keep mutual cooperation in such situations? Using the laboratory ex ime t and simple multi –Prisoner’s dilemma, we explore the effect of the change in the number of contacts and in the payoff structure, and then the characteristics of the strategy that leads players to reach mutual cooperation. When the number of contacts increases from one to two, players face with the more complicated situation and their behavior may be different from the single contact. The change of payoff structure will also affect their behavior. In such a case, finding the decision making to facilitate cooperation may be a hint for solving real problems.