Cohesion , equivalence , and similarity of behavior : a theoretical and empirical assessment *

Network analysts have debated the extent to which cohesion versus structural equivalence serves as a source of similar behavior among actors. More recently, role equivalence has emerged as an alternative to structural equivalence. Using data on the contribution patterns of corporate political action committees, I examine the effect of various indicators of cohesion, structural equivalence, and role equivalence on the extent to which firms behave similarly. Although various operationalizations of all three concepts are correlated with similar behavior, the most consistent predictor is the joint prominence of two firms in the network. I argue that this common location in central positions is a form of role equivalence, but one that is distinct from conventional definitions of the concept. I then suggest a distinction between what I term ‘central’ and ‘peripheral’ role equivalence.