for their helpful comments on this manuscript. The first author gratefully acknowledges the support of INSEAD where he was a visiting professor. An earlier version of this paper received the Academy of Management, Organization and Management Theory's Division Best Paper Award for 1997.This theory-development case study of the quality circle management fashion focuses on three features of management-knowledge entrepreneurs' discourse promoting or discrediting such fashions: its lifecycle, forces triggering stages in its lifecycle, and the type of collective learning it fostered. Results suggest, first, that variability in when different types of knowledge entrepreneurs begin, continue, and stop promoting fashions explains variability in their lifecycles; second, that historically unique conjunctions of forces, endogenous and exogenous to the management-fashion market, trigger and shape management fashions; and third, that emotionally charged, enthusiastic, and unreasoned discourse characterizes the upswings of management fashion waves, whereas more reasoned, unemotional, and qualified discourse characterizes their downswings, evidencing a pattern of superstitious collective learning.'Organizational theorists who study management discoursewhat is said and written about management-related issueshave focused on discourse promoting techniques for managing organizations and their employees (Abrahamson, 1989(Abrahamson, , 1997 Barley and Kunda, 1992; Guill6n, 1994;Shenhav, 1995). This focus has originated in part from the claim that managers use discourse about management techniques to communicate to organizational stakeholders that their organizations conform to institutional norms mandating the use of these techniques (Meyer and Rowan, 1977). More recently, the importance of such management discourse has been further underscored by the proposition that it also enables the diffusion of management techniques across thousands of dissimilar organizations (Abrahamson, 1991). It does so by reinforcing the belief that these organizations are similar in ways that would cause them to benefit equally from adopting a management technique (Strang and Meyer, 1994). For example, discourse claiming that all U.S. organizations, like all Japanese organizations, would benefit from using socalled Japanese management techniques may have impelled the widespread diffusion of these techniques across thousands of disparate U.S. organizations during the 1980s and early 1990s. The notion that management discourse matters because it shapes the diffusion of management techniques has also drawn attention to the knowledge entrepreneurs who produce such discourse-management consultants, for example-and to their interests in disseminating discourse promoting certain management techniques in order to trigger their diffusion (