In the early treatments of organizational environments two main approaches were apparent. One conceptualized environmental features primarily in individual-level psychological terms, emphasizing perceived environmental uncertainty (Emery & Trist, 1965, Terryberry, 1968; Thompson, 1967). The other approach took a more relational, macro, network view, conceptualizing environments in terms of interorganizational relationships (Clark, 1965; Etzioni, 1960; Hage and Aiken, 1969; Levine & White, 1961; Litwak & HyIton, 1962; Warren, 1967; Wigand, 1979). Since these seminal studies, the interorganizational network approach continues to be actively pursued. More sensitive structural analysis of interorganizational relations has been developed and linked to a range of variables (for a review see Eisenberg et aI., 1985).