15 January 2024This article deals with the integration of industry-level markup targets into oligopoly theory. Itproposes a behavioral competition model in which firms use the average cost-plus price to determine theirsupplies. Specifically, firms are assumed to increase (resp., decrease) their supplies as the market pricerises over (resp., falls below) this reference price. The equilibrium market outcome lies between thosecorresponding to Bertrand and Cournot competition. It depends on the industry’s margin target, whichdetermines the slope of firms’ supply functions. The more significant the markup target is, the lowerare the firms’ equilibrium supplies at any price level and the higher is the equilibrium market price. Anindustry-wide commitment to targeting a markup thus reduces competition in equilibrium. The reductionin competition is more pronounced than when firms commit to linear supply functions.Keywords: supply function, markup pricing, price fixing, oligopoly.