This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordPolitical activity is conventionally considered a constitutive feature of interest groups, underpinning an impressive literature on the strategies groups employ to exercise political influence. Whether and how intensely voluntary membership groups engage in political activities to start with, however, is rarely examined. We present a new incentive-theoretical perspective on group political activity, considering both member demands and leadership constraints. We argue that investments in political activities (one way of generating collective incentives) as a means to prevent member exit are more or less important depending on a group’s composition. Simultaneously, the extent to which leaders are incentivized to cater to members’ demands when trying to balance these against conflicting demands, depends on communication channels between leaders and members and the importance of membership fees. Applying Bayesian ordered logit models to data from two group surveys supports our perspective and stresses the importance of considering how intra-organizational dynamics steer groups’ external activities
