Transforming climate policy networks: the role of belief homophily in network formation

Research on social and policy networks frequently show that actors tend to favor ties to similar alters. When actors choose to form ties to like-minded others, research talks about belief homophily. It has been shown, that even small tendencies of homophily may eventually lead to a strongly polarized network structure, which, in the context of policy networks, is assumed to cause problems for example in decision making. Attempts to better understand how this mechanism transforms networks over time has been mostly based on studies using simulated data, while real life empirical analyses have, for the most part, dealt with the issue as a static phenomenon. In this paper we propose that existing levels of belief homophily in a policy network effect how the network transforms in time. The assumption is, that higher levels of belief homophily lead to more polarized network structures faster, while networks with reasonably low levels of belief homophily remain more stable. We use longitudinal policy network survey data from four countries that are different in how strongly belief homophily has contributed to the network formation. In Ireland belief homophily has previously played a reasonably small role in organizational collaboration, in Finland and Sweden the effect has been moderate, and high in Australia. The analysis is conducted with exponential random graph models.