Structural Presumptions for Non-horizontal Mergers in the 2023 Merger Guidelines: A Primer and a Path Forward

The 2023 Merger Guidelines (MGs) change the Agencies’ narrative regarding non-horizontal mergers. They follow a four-pronged approach: (1) They blend horizontal and non-horizontal mergers. (2) They simplify the narrative about non-horizontal mergers. (3) They consoli- date and broaden the theories of harm in non-horizontal mergers. (4) They blend economics and law analysis. In this article, we elaborate on these points. We discuss how the MGs’ an- ticompetitive presumptions apply to non-horizontal mergers, relate them to the economics literature, and provide examples. We finish discussing the economic rationale of the struc- tural presumption involving rivals’ exit concerns due to the exercise of market power and propose a path forward.