Conceptual frameworks for the analysis of common property regimes are important because they allow for the comparison of individual cases and generalisation across diversity. The framework proposed by Oakerson (1986) is critically examined and although many of its features are useful and worth retaining, it is found to be inadequate in its treatment of the key issues of power and authority, on the one hand, and of social and economic structure, on the other. Struggles over access to and control over common property resources often arise from structural inequalities which have to be made central to analysis. The Oakerson model also tends to neglect the importance of ecological dynamics and does not make sufficient provision for disjunctions between technical and ecological aspects. Modifications are suggested which allow for the analysis of these dimensions. This "political economy" model of the commons is put to the test by applying it to the analysis of grazing management schemes in the Communal Lands of Zimbabwe. Detailed ethnographic data on the complexities of intra-community power struggles in one such scheme are briefly summarised, and the model is used to diagnose the underlying reasons for the problems which have emerged within this scheme.