This game was played in the Economic Science Lab's teaching lab in 1996. Twenty terminals were available, so some terminals had two students acting as a single player. Participants were randomly matched into pairs, anonymously, before play began. These pairings remained the same throughout the session. Participants were told they would play the Prisoners' Dilemma game described in In-Class Game #2, and they were told that they would play it many times (but they were not told how many times). After about a half-hour of play, they were told there would be only five more periods. A player's payoff for the repeated game was the average of his or her payoffs for all the plays, and these were then converted into quiz points. Exercsise Set #5 provides an analysis of the repeated Prisoners' Dilemma.
Up Down
Up 3, 3 5, 1
Down 1, 5 4, 4
1 = Cooperate = Down 0 = Defect = Up
Pair1 Pair2 Pair3 Pair4 Pair5 Pair6 Pair7 Pair8 Pair9 Pair10
t A B A B A B A B A B A B A B A B A B A B
1 1 1 1 0 0 1 1 0 0 1 0 1 1 1 1 1 1 0 0 1
2 1 1 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 0 0 0
3 1 1 0 0 0 1 0 0 0 0 1 0 1 1 1 1 1 0 0 0
4 1 1 0 1 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
5 1 1 1 0 1 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
6 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
7 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 1 0
8 1 1 0 0 1 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
9 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
10 1 1 0 1 0 0 0 0 0 0 1 1 1 1 1 1 0 0 1 0
11 1 1 1 0 0 1 0 0 0 0 1 1 1 1 1 1 0 0 1 0
12 1 1 0 0 1 1 0 0 0 0 1 1 1 1 1 1 0 0 0 0
13 1 1 0 0 1 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
14 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
15 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0
16 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 1 0 0
17 1 1 0 0 1 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
18 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
19 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
20 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
21 1 1 0 0 0 1 0 0 0 0 1 1 1 1 1 1 1 1 0 0
22 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
23 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
24 1 1 1 0 1 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0
25 1 1 1 0 1 0 0 0 0 0 1 1 1 1 1 1 0 1 0 0
26 1 1 1 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0
27 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0
28 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0
29 1 1 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0
30 1 1 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 0 0 0
31 0 1 0 0 1 0 0 0 0 0
32 1 0 0 0 0 0 0 0 0 0
33 0 1 0 0 0 0 0 0 0 0
34 0 0 0 0 0 1 0 0 0 0
35 0 0 0 0 0 0 0 0 0 0
A: 137 97 105 101 105 116 120 115 96 86
B: 133 113 109 109 105 112 120 115 100 94
A: 3.91 2.77 3.00 2.89 3.00 3.87 4.00 3.83 3.20 2.87
B: 3.80 3.23 3.11 3.11 3.00 3.73 4.00 3.83 3.33 3.13
Players in each pair are identified as Player A and Player B. The rows at the bottom show the total payoffs and the average payoffs. (The game was implemented from two master/monitor terminals, five pairs to each; this explains why half the pairs played more periods than the other pairs.)