International policy diffusion at the systemic level: Linking micro patterns to macro dynamism

This article tries to identify the conditions under which international policy diffusion occurs, focusing on networks among states. In the existing policy diffusion literature, ‘networks’ have recently attracted the attention of scholars. Using Agent-Based Simulation, we consider the question of whether a new policy diffuses more widely in a community with dense networks or in a community with sparse networks. Our results show that denser networks do not always lead to more diffusion. Moreover, we find that ‘network structure’, namely whether easily affected states are connected to innovators, greatly determines the outcome of policy diffusion. Conducting a deductive thought-experiment rather than inductive (mainly statistical) analysis, our research presents a counter-intuitive result concerning the effects of network density on policy diffusion. In addition, we make a contribution to the methodology of international relations by attempting to bridge the unit- and system-levels.