Abstract
This article treats the emergence and preservation of cooperation in the finitely repeated prisoner's dilemma. Cooperative behavior in the iterated prisoner's dilemma has often been observed, even if the number of repetition is finite and fixed. But it is asserted in theory that players will defect from the very beginning in the finitely repeated prisoner's dilemma. From the evolutionary point of view, this breakdown of cooperation is translated as a gradual decline of cooperation.
On this subject, Shimizu (1996) reveals the emerging process of cooperation from the follow-up study of Axelrod's simulation. In this paper, we examine the “gradual decline” of cooperation from our new simulation. We will show that when the nature of the interactions is long enough term, the gradual decline takes very long time. Therefore cooperation can be regarded as stable in practice.
