The Persistence of Goodness

Experimental evidence and economic examples like Basu's (1984) taxi-driver problem illustrate that many people are honest (or good) even when beyond the reach of the law, and without repeated interactions or reputation effects. We provide game-theoretic underpinnings of the level of goodness in a population. For appropriate parameter ranges, a certain level of good behaviour will emerge as an evolutionarily stable equilibrium: virtue will not be driven out of the population, even in a Darwinian world of the survival of the fittest. The long-run equilibrium proportion of good behaviour is independent of the level of intrinsic goodness.