From the perspective of the Institutional Analysis and Development Framework (IAD) and the evolutionary game theory we analyze the role of the voluntary environmental action in tourism economies where there are common-pool resources. We show the conditions that allow voluntary unilateral commitments. We also analyze the determinants of ecolabels? success, that is, the costs and price premiums associated with the ecolabel scheme, the number and composition of promoter firms, the degree of adoption of environmental unilateral commitments when the ecolabel is launched and finally, the state and number of users of the common-pool resource. Lastly, we show how the ecolabel can trigger an improvement in the common-pool resource.