Predatory Buying and the Antitrust Laws

The use of price to injure competition on the buying side of a market and thereby increase monopsony profits cannot be dismissed as theoretically implausible, but there are reasons to believe the practice is uncommon. Monopsony and monopoly are economically symmetrical, and both reduce efficiency by distorting the allocation of resources. A coherent antitrust policy designed to maximize wealth would treat monopsony and monopoly as equivalents. For that reason, exclusionary behavior is equally objectionable whether it increases monopsony power or monopoly power.

The fact that an increase in monopsony power may have little impact on consumers does not mitigate the antitrust concern, because the negative impact on sellers by itself warrants equal antitrust concern, a point oddly unacknowledged by the Supreme Court in its Weyerhauser decision.