The primary evidence about the factors determining successful self-governance of common-pool resources (CPR) has come from case studies. More recently, this observational evidence has been complemented by insights from economic experiments. Here we advance a third approach in which the role of local deliberation about the management of a ﬁshery resource is investigated in a ﬁeld experiment. Using three control and three treatment communities in a freshwater ﬁshery, we tested whether participation in developing speciﬁc measures for community-based sustainable CPR management increased the willingness to contribute to the implementation of these measures. Each community was also exposed to information about their community leaders' advice about the proposed measures. Both participation and leader advice affected the willingness of participants to contribute in one of three proposed measures. However, the strongest inﬂuence on individual willingness to contribute was exerted by the individual beliefs about the cooperation of others in CPR management.