Why Social Movement Sympathizers Don't Participate: Erosion and Nonconversion of Support

Social movement organizations face the challenge of converting action preparedness into action participation, and accordingly, they must deal with factors that lead to nonparticipation. We identify two routes to nonparticipationnonconversion and Nonconversion refers to a movement's failure to transform sympathizers into active participants. Erosion refers to the loss of sympathizers. We provide a theoretical framework for explaining nonconversion and erosion and apply it to a longitudinal study of a mobilization campaign of the Dutch Peace Movement: the People's Petition against cruise missiles. Data came from telephone interviews we conducted among random samples (N = 224) from the populations of four communities before and after the campaign (in May and November 1985). We use binomial logistic regression analyses to test several explanations of nonconversion and erosion. Factors that led to erosion were moderate action preparedness at the beginning of the campaign, declining preparedness during the campaign, and a social environment perceived by participants as becoming less and less supportive. Factors that led to nonconversion were moderate but stable action preparedness combined with the presence of barriers to action and an indifferent social environment. Results are discussed and related to social movement literature.