Most retrospective merger studies resort to the treatment effect approach, comparing the price dynamics in a treatment group and in a control group. We propose a systematic method to construct the groups, which applies to any industry with spatial competition. The method is consistent with the...

Asymmetric information in procurement entails double marginalization. The phenomenon is most severe when the buyer has all the bargaining power at the production stage, while it vanishes when the buyer and suppliers' weights are balanced. Vertical integration eliminates double marginalization...