Coevolution of Networks and Beliefs in U.S. Environmental Risk Policy

Networks are an important part of the environmental policy process as they influence the ability of actors to synthesize information and learn to manage complex risks. According to the Advocacy Coalition Framework, the dynamics of policy network formation lead to structures exhibiting belief-oriented segregation—that is, a high correspondence between shared beliefs and policy-relevant interactions. These structures may be produced through at least two pathways: belief homophily, where actors actively seek out connections with others sharing their belief system, and policy-oriented learning, where connected actors become more similar in their beliefs. The cross-sectional design of much policy research does not allow an examination of these potentially complementary forces that shape belief systems and networks. These dynamics are studied using data on policy beliefs and networking in the U.S. environmental risk policy subsystem across two time periods, 1985 and 2000 (N = 223). Results indicate strong homophily effects, but relatively weak learning effects in the evolution of this policy network. This study helps pave the way for additional research on the dynamics shaping policy networks and beliefs, and helps to clarify the differences between individual versus organizational contributions to policy network evolution.