Contributions by Interest Groups to Lobbying Coalitions

Decisions by interest groups about when and how to work together inside coalitions are critical components of interest group strategies. This article argues that the composition of lobbying coalitions is a key factor that relates to these decisions. First, partisan diversity within a coalition may enhance contributions from groups if bipartisanship is seen as a positive signal of the coalition's likely success. Second, network embeddedness may enhance contributions from coalition members if concomitant relationships make it easier to collaborate. Using a two-mode exponential random graph model with structural zeros, the study draws on interviews with congressional staff members, interest group representatives, and coalition representatives working on health policy in the United States. The results demonstrate a robust, positive association of partisan diversity with contributions by interest groups to lobbying coalitions. The results also reveal positive correspondence with network embeddedness, although these results are contingent on model specification.