PROFESSIONALIZATION AND PROTEST - CHANGES IN THE SOCIAL-MOVEMENT SECTOR, 1961-1983

Social movement organizations (SMOs) operate in a multiorganizational field known as the social movement sector. Although it is generally agreed that an organization's environment affects the outcomes associated with that organization, little research exists regarding characteristics and trends in the social movement sector. By examining changes in an activity common to SMOs, I assess claims in the social movement literature concerning the professionalization of the sector and its effects on the sector's size, relations, and composition. Using data on protest demonstrations in Washington, D.C., between 1961 and 1983 (N=485), I show that interorganizational relations in the sector have become denser as the number and differentiation of organizations has increased. I present evidence that organizers have moderated their tactical and ideological approaches in efforts to expand their appeal, resulting in an increase in individual participation.