and seminar participants at the University of Illinois and the University of California at Berkeley. We also thank Christine Oliver and three anonymous reviewers for their valuable comments on earlier drafts.This study examines whether board interlock ties facilitate second-order imitation, in which firms imitate an underlying decision process that can be adapted to multiple policy domains, rather than imitating specific policies of tied-to firms (first-order imitation). Longitudinal analyses of archival data for a large sample of Forbes/Fortune 500 companies, as well as analyses of survey data on mimetic processes among these firms, show that network ties to firms that use imitation to determine a particular policy can prompt use of imitation by the focal firm in determining both that policy and a different policy. Firms that have board network ties to firms in other industries that imitate their competitors' business strategy are likely to imitate their own competitors' business strategy, as well as their competitors' acquisition activity and compensation policy. Thus, the findings reveal network effects that are not visible with extant perspectives on interorganizational imitation. We discuss implications for institutional theory and research on interorganizational networks.-A long tradition of research in organization theory has examined the diffusion of technology, policy, and strategy through social networks (Burt, 1987; Mizruchi, 1996). One of the most important propositions in this literature is that, under conditions of uncertainty, social influence processes will lead firms to imitate the individual policy decisions of other firms to which they are connected by social network ties (DiMaggio and Powell, 1983;Galaskiewicz, 1985). Empirical studies in the board interlocks literature, in particular, have examined how overlapping board memberships between firms may facilitate the imitation of particular organizational structures, such as the multidivisional form, or individual policy decisions, such as the adoption of poison pills (e.g., Davis, 1991; Palmer, Jennings, and Zhou, 1993; Haunschild, 1993; Westphal and Zajac, 1997). Prior research may have underestimated the magnitude of network effects, however, by restricting its focus to first-order imitation, or the act of imitating the content of a particular policy decision, such as the level of spending on research and development (R&D). Second-order imitation, or the imitation of an underlying decision process or script that can be adapted to multiple policy domains (e.g., business strategy, compensation policy, acquisition activity, etc.), has been ignored in the interlocks literature, despite a body of literature on second-order effects.In general, second-order phenomena are characterized by an underlying process mechanism that can explain multiple discrete first-order effects (e.g., Bartunek and Moch, 1987;Farmer et al., 1997). In the organizational behavior literature, for instance, researchers have invoked the notion of secondorder change to describe...