Higher education policy has been subject to considerable reform in OECD states over the past two decades. Some states have introduced tuition fees, others have massively increased public funding for higher education, and still others remain in stasis, retaining the elitist model with which they began the postwar era. This article develops the argument that higher education policy in the OECD is driven by a set of partisan choices within a trilemma between the level of enrollment, the degree of subsidization, and the overall public cost of higher education. The author develops a formal model of the micromechanisms underlying movements within this trilemma, noting the importance of partisan politics, existing enrollment, tax structure, and access. These propositions are tested statistically on a sample of twenty-two OECD countries and through case histories of higher education reform in England, Sweden, and Germany.