policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each …

examples where courts have approved highly concentrating mergers based on limited evidence of entry and expansion. We show …

Economists widely agree that, absent sufficient efficiencies or other offsetting factors, mergers that increase … in the antitrust review of mergers is sensible and economically well-founded. It might seem natural to determine whether …

Worldwide, the overwhelming majority of large horizontal mergers are cleared by antitrust authorities unconditionally …. The presumption seems to be that efficiencies from these mergers are sizeable. We calculate the compensating efficiencies … that would prevent a merger from harming consumers for 1,014 mergers affecting 12,325 antitrust markets scrutinized by the …

merger enforcement. The policy debate shows that one of the key arguments put forward when supporting potential mergers is … little empirical evidence on the actual effects of realized mergers on cost efficiencies. We exploit a large and highly …