Predatory selling has been evaluated and assessed by antitrust regulators, the courts, and the economics profession. Recently the spotlight has turned to alleged predatory buying. The criteria for determining in output markets whether monopolists or oligopolists are engaged in predatory actions...

The lens used by the courts and much of the antitrust literature on predatory selling and/or buying is based on partial equilibrium methodology. We demonstrate that such methodology is unreliable for assessments of predatory monopoly or monopsony conduct. In contrast to the typical two-stage...