Cooperation against all predictions

In Binary Threshold Public Good (BTPG) games, n players have binary choices: cooperation or non-cooperation. If at least k cooperate, a public good is produced. The case = the Stag Hunt game with two pure strategy equilibria E1 (all cooperate) and E0 (no player cooperates). four rather diverse examples of four-player three prominent concepts equilibrium selection favor E0. Experiments, however, result in frequencies between 70.3% 99.7%. Also for < n, selected clearly differ from experimental behavior. We interpret our observations by suggesting concept Behavioral Equilibrium Selection.