Although the concept of sustainable development is gaining increasing political acknowledgement, despite the implementation of environmental policies specifically intended to solve problems in this area, environmental degradation resulting from the recurrent problems associated with the over-exploitation of natural resources remains an important concern for most countries. How can this situation be explained? This article postulates that a combination of approaches from the political sciences (in particular policy analysis) and institutional economics would enable the identification of the most relevant regulatory dimensions which can explain the (un)sustainable uses of resources. Based on this starting point, it develops an innovative theoretical framework, i.e. that of the Institutional Resource Regime (IRR). The adopted approach facilitates the analysis of the regulatory measures and resource management practices associated with complex and competitive heterogeneous use situations from a perspective of sustainability. Indeed, the two dimensions of “extent” and “coherence” enable the definition and categorization of the IRR of a given resource. The extent of an IRR refers to the total number of goods and services in use that are actually regulated by the regime at a given time, while the coherence measures the degree of coordination of the various user-actors within the regime. One of the major contributions of the IRR framework is its ability to describe the different configurations of regimes, both theoretically and empirically, and to predict their effect on the sustainability of a resource based on the hypothesis that high levels of regime extent and coherence are necessary preconditions for sustainability.