Sociologists have turned to collective identity to fill gaps in resource mo
bilization and political process accounts of the emergence, trajectories, a
nd impacts of social movements. Collective identity has been treated as an
alternative to structurally given interests in accounting for the claims on
behalf of which people mobilize, an alternative to selective incentives in
understanding why people participate, an alternative to instrumental ratio
nality in explaining what tactical choices activists make, and an alternati
ve to institutional reforms in assessing movements' impacts. Collective ide
ntity has been treated both too broadly and too narrowly, sometimes applied
to too many dynamics, at other times made into a residual category within
structuralist, state-centered, and rationalist accounts.