I analyse the effects of a downstream merger in a differentiated oligopoly when there is bargaining between downstream firms and upstream agents (firms or unions). Bargaining outcomes can be observable or unobservable by rivals. When competition is in quantities, upstream agents are independent...

Using a comprehensive dataset on the incidence of price-fixing across British manufacturing industries in the 1950s, I compare collusive and competitive industries and find evidence of a negative relationship between collusion and the labour productivity of larger firms relative to smaller...