Growing concern about large digital platform companies, particularly Google,Facebook, Amazon, and Apple, exercising monopoly power has given rise to antitrustinvestigations that examine whether they are guilty of exclusionary practices.After defending the consumer welfare standard as the basis for decisions,this paper explores whether the market power and conduct of each company

justifies antitrust action. Whether to pursue such action should be based partlyon a counterfactual analysis of the consequences of the likely remedies that wouldbe applied if a company is found guilty. Remedies, such as divestiture of acquiredfirms or structural separation of vertically integrated firms, would likely harmconsumers who benefit from lower costs and increased innovation that resultfrom combining complementary products into one ecosystem. This paper arguesagainst a more activist antitrust policy considering the knowledge and incentivesof the courts and those who enforce it. It is difficult to accurately assess the effectsof firm conduct on consumer welfare, and enforcement agencies’ decisions maynot be based entirely on objective analysis but on political pressure, sometimesfrom a firm’s competitors. Instead of pursuing more activist antitrust policy, thegovernment should remove barriers that keep firms from entering new marketsand competing vigorously.