Interstate professional associations and the diffusion of policy innovations

Although scholars have found that policy innovations diffuse across states in a systematic manner, they generally have not examined the role that individuals and institutions play in promoting diffusion. I posit that interstate professional associations provide institutional foundations for the development and dissemination of innovations by state officials with jurisdiction over particular policy areas. I test this hypothesis by examining the determinants of state adoption of the Health Maintenance Organization (HMO) Model Act, a comprehensive set of regulations developed by the National Association of Insurance Commissioners (NAIC). My central finding is that states whose insurance commissioner participated in the NAIC's Accident and Health Insurance Committee, which has jurisdiction over HMO regulation, were more likely than other states to adopt the Model Act. This result provides evidence that associations can affect policy diffusion. It also sharpens the conventional wisdom by highlighting a specific institutional arrangement-a committee system-through which participation in associations can facilitate the adoption of innovations.