Reanalyzing 12 experiments on the repeated prisoner’s dilemma (PD), we robustly observe

three distinct subject types: defectors, cautious cooperators and strong cooperators.

The strategies used by these types are surprisingly stable across experiments and

uncorrelated with treatment parameters, but their population shares are highly correlated

with treatment parameters. As the discount factor increases, the shares of defectors decrease

and the relative shares of strong cooperators increase. Structurally analyzing behavior,

we next find that subjects have limited foresight and assign values to all states of

the supergame, which relate to the original stage-game payoffs in a manner compatible

with inequity aversion. This induces the structure of coordination games and approximately

explains the strategies played using Schelling’s focal points: after (*c;c*) subjects

play according to the coordination game’s cooperative equilibrium, after (*d;d*) they play

according to its defective equilibrium, and after (*c;d*) or (*d;c*) they play according to its

mixed equilibrium.