The common-pool problem has become a popular metaphor in studies of distributive politics, multi-party government and public finance, where it refers to overexploitation problems similar to those often encountered in the management of physical resources. There has been little discussion on what the fiscal commons actually is, and therefore it is not obvious that the conclusions drawn from these studies are always useful. This article proposes a conceptual apparatus for analysing the fiscal commons and suggests how the metaphor could be used in new applications, on the one hand, and why some previous results should be used with caution, on the other. Special attention should be paid to the specification of the bargaining situation in which decisions are made as well as to the feedback loops that connect the choice of policy instruments to the economy and again to the political process.