Legitimate punishment, feedback, and the enforcement of cooperation

► We experimentally test a 'legitimate punishment' institution within a public goods game framework and compare it to a classic (discretionary) punishment mechanism. ► Restrictions rule out antisocial punishment, a phenomenon which may undermine the scope for self-governance. ► We show that the introduction of legitimate punishment leads to higher cooperation and substantial efficiency gains. ► We also find that removing the information over high contributorsʼ choices is sufficient to generate a dramatic decline in cooperation rates and earnings.