Network Structure and the Efficiency Gains from Mergers: Evidence from U.S. Freight Railroads
利用美国货运铁路1985-2005年交易数据，量化并购带来的成本效率提升，发现并购使运输成本降低12.9%、价格降低8.8%，但加价增加7.2%。
ABSTRACT The trade‐off between market power and efficiency gains is central to antitrust analyses of mergers, but empirical evidence quantifying efficiencies remains limited. Using transaction‐level data from U.S. freight railroads (1985–2005), this article quantifies merger‐induced cost efficiencies, driven mainly by eliminating inter‐railroad interchange costs and reoptimization of routing and resource allocation within integrated networks. I develop a spatial equilibrium model with oligopolistic competition to assess equilibrium merger effects. Counterfactual analyses show mergers reduce shipment costs by 12.9% and prices by 8.8%. Markups increase by 7.2%, driven primarily by non‐merging firms reallocating resources away from regions where merged firms achieve large cost reductions.