Behavior in repeated prisoner's dilemma games with shifted outcomes analyzed with a statistical learning model

We address whether cooperative behavior in a repeated Prisoner's Dilemma (PD) is more easily achieved under "good circumstances" (all payoffs in the constituent PD are positive), "bad circumstances" (payoffs are negative), or "mixed circumstances." To analyze the behavior in these repeated PDs, we developed and applied a learning model that improves upon standard learning models in two ways: (1) It allows for statistical tests of the parameter estimates, and (2) it allows for the incorporation of independent variables (e.g., subject or game characteristics). The model is applied to the data of the repeated PD experiment in van Assen and Snijders (20042005). Our findings demonstrate that our model can be used to identify and test how learning differs across persons and across different circumstances.