Properties of supranational governance structures and policy diffusion: The case of mifepristone approvals

Many studies show that supranational governance structures (SGS)—understood as international organizations or international treaties—contribute to the global diffusion of public policies. However, we still have a limited understanding of which properties of SGS hasten the number of policy adoptions. To advance this literature, we argue that SGS making legally binding and univocal claims are more likely to act as diffusion accelerators. We demonstrate the suitability of this argument through a case study of the global diffusion of mifepristone approvals, a single-purpose medicine to terminate pregnancies that has revolutionized abortion services. The analysis supports our expectation. Links to the EU and the Maputo Protocol—the only two considered SGS that make binding claims with clear implications for this policy field—hasten mifepristone approvals. By contrast, ratification of four other treaties—that do not make binding and univocal claims—and exposure to World Health Organization guidelines on medical abortion does not hasten these approvals.