Do international parliaments matter? An empirical analysis of influences on foreign policy and civil rights

International parliamentary institutions (IPIs), which give parliamentarians regular opportunities to communicate with their foreign counterparts, have become a common feature in global governance. Recent research has shed light on why IPIs are created, on the similarities and differences in their institutional design, and on the reasons that lead members of national parliaments to engage with them. By contrast, there is little systematic empirical research on whether and how IPIs affect global politics. This article addresses this question by assessing their ability to influence states in relation to the position they take on issues of global concern and to how they treat their own citizens. The study identifies several mechanisms of IPI influence, leading to the hypothesis that more frequent opportunities for parliamentarians to interact with their foreign counterparts within IPIs leads in time to greater similarity in the foreign policy positions expressed by their governments and affects how those governments protect the civil rights of their citizens. A statistical analysis spanning multiple international organizations, member states, and decades indicates that IPIs offer a distinct contribution to convergence in foreign policy. By contrast, participation in IPIs is not robustly associated with civil rights protections. The finding that IPIs can be consequential on which policies governments promote internationally even though such institutions typically lack substantial authority may be encouraging for advocates of further international parliamentarization and specifically the creation of a United Nations parliamentary assembly.