A Holy Alliance: Collusion in the Renaissance Europe Alum Market

On June 11, 1470, representatives of Pope Paul II and Ferdinand, King of Naples concluded a cartel agreement to restrict competition in the sale of alum. The agreement was one element of a broader plan to monopolize the sale of alum throughout Christendom. We discuss the background of the cartel agreement and analyze its terms (which include arrangements to facilitate detection of and reduce the profitability of defection) and the constraints that limited, but did not eliminate, Rome’s ability to extract economic profit from the European alum market.