The structure of coordination: transatlantic policy networks and the mobilization of business and civil society

External policy networks resolve two collective action problems in EU external relations: engaging nonstate actors from the EU and its partner countries in transnational policymaking and converting this engagement to feedback for policymakers. We use formal network analysis to understand the relationship between network structure and collective action by transnational nonstate actors. Our empirical focus is on the Transatlantic Business Council and the Transatlantic Consumer Dialogue networks, which engage business and consumer advocacy organizations in transatlantic economic policymaking. We find that both are highly centralized around EU and US government institutions, with relatively low, but rising, levels of interaction among nonstate organizations. This structure helps increase engagement by giving organizations opportunities to interact with government institutions, learn from their peers, and, for some, to exercise power. It also helps EU and US institutions harness policy feedback, especially from nonstate actors that have frequent interactions with their peers.