There is a widespread belief that increases in the cross-border integration of markets are associated with increases in global concentration along various dimensions. This article reviews the available evidence and presents new data indicating that increasing global integration has not been accompanied by general increases in four types of global concentration measures: industry seller concentration, cross-industry superconcentration, national/regional hegemony, and geographic concentration. The article also discusses the possible causes and consequences of a systematic bias towards believing in increasing concentration, as well as some practical remedies.