When a downstream firm buys an input supplier, it can reduce its costs of using that input. Other input suppliers typically respond by pricing more aggressively, given the demand reduction, which tends to lower input supply costs to other firms. Thus, a vertical merger may lower rivals' costs...

On both sides of the Atlantic, the regulation of gas transmission networks has undergone major changes since the early 1990s. Whereas in the US, the long-standing regime of cost-plus regulation was complemented by increasing pipe-to-pipe competition, most European countries moved towards...