Prisoner's Dilemma (Push and Pull) Guide

Aa

The game is a classic prisoner's dilemma, but the framing may obscure this fact. Each student is matched with another over a number of rounds. In each round, each chooses between Pull (akin to defect) or Push (akin to cooperate). Actions and payoffs are revealed after each round.

Learning Objective 1: Equilibrium in the Prisoner's Dilemma

In a one-shot prisoner's dilemma, defect is the dominant strategy. The Nash equilibrium is therefore for each player to defect (choose Pull) despite the fact that cooperation (both choosing Push) maximizes overall payoffs.

Learning Objective 2: Facilitating Cooperative Outcomes

Communication and indefinite repetition may facilitate cooperative outcomes (choosing Push).

With the default parameters, Pull increases the player's own payoffs by $300 while Push instead increases the other's payoff by $400. Each pair plays 5 rounds, which should lead to Nash-equilibrium play for most pairs in the final round, particularly if the number of rounds is announced in advance.

Allowing Chat will generally lead to more cooperative behavior. Not revealing the number of rounds will also lead to an increase in students choosing Push, the cooperative action.

Another way to increase cooperative behavior is to increase the Push amount ($400 by default) relative to the Pull amount ($300 by default).

The results screen presents a graph, a table, and raw data, each focusing on the likelihood of the actions.

Use the View menu (Figure 1) to select a different game if you have run multiple games in your playlist. If not, this option is not available. If you used one of the Replay options, you can contrast the results between these linked games using the Compare button. To obtain a screen shot of the results, you can use the Download button beneath the compare button.

The Tables tab generates a table (Figure 2) indicating the percentage of students choosing each action in each round.

The Graphs tab presents this information in a slightly different way using charts (Figure 3). It shows for each round the average choices and the incidence of the three outcomes: both played Pull; both played Push; and one played Push while the other played Pull. It is likely that groups playing Push/Pull in early rounds will convert to Pull/Pull in later rounds.

Note: The chart has dynamic elements. Click the checkboxes in the legend to hide a particular category. Also, mousing over a label in the legend highlights the corresponding bars in the chart.

The Raw Data tab (Figure 4) presents a player table with each player's choice, their group, and the round number in a table format. This table presents the data from the game that has not been processed in any particular way.

tiled icons

ncG1vNJzZmirY2LCtHnWnqqtZWJjrq6t2ailmq%2BjY7CwuY6mppukkZd6rq3Nrpilq1%2BmwqqvyqyrmqqkZL22v8eprKWkXp3Brrg%3D