Law Commons^™

Market Power Without Market Definition, Daniel A. Crane

Articles

Antitrust law has traditionally required proof of market power in most cases and has analyzed market power through a market definition/market share lens. In recent years, this indirect or structural approach to proving market power has come under attack as misguided in practice and intellectually incoherent. If market definition collapses in the courts and antitrust agencies, as it seems poised to do, this will rupture antitrust analysis and create urgent pressures for an alternative approach to proving market power through direct evidence. None of the leading theoretic approaches—such as the Lerner Index or a search for supracompetitive profits—provides a robust …