It is well known that an optimal merger policy requires consideration of efficiencies in enforcement decisions. However, as understanding of a market's equilibrium structure is required to integrate the efficiency defense into a merger analysis, efficiency evaluations are controversial. New...

Most mergers filed at the enforcement agencies are conglomerate in nature with only minor horizontal overlaps. An enforcement agency may challenge the merger, if any overlap is believed to be adversely affected by the transaction. While the merging firm is entitled to a hearing in federal court,...

The European Union (EU) and the United States (US) enforce the world's two best known merger policies. The EU addresses transactions that are likely to impede effective competition, historically, with some type of dominance analysis, while the US focuses on mergers that are likely to...

The Hart Scott Rodino program, coupled with the modern Merger Guidelines has structured merger enforcement for the last twenty years. This paper reviews all of the filings on which the Commission issued a second request. While horizontal mergers predominate, vertical, potential competition and...