This article investigates the nature and role of authority contests—the claims and counterclaims about whose ideas matter on policy debates and via what procedures they should be heard—in policy paradigm contestation, reform and abandonment. Examining the authority contests around prairie Canada's grain marketing policy illustrates an additional pathway—a value-driven model—to Hall's model of endogenous policy anomalies. It further documents differences across governments in how they resolve contentious policy debates, showing that governments make fewer efforts to supplement their own representational authority with expert and/or popular authority when they enjoy majoritarian support from the affected region than when they do not and when their support for paradigm change is value-driven rather than a response to policy anomalies.