Tariff Shocks as Natural Experiments: Pass-Through, Market Structure, and Antitrust Risk

Tariffs are typically viewed as instruments of trade policy, but they also provide valuable natural experiments for understanding competition and antitrust risk. Because tariffs impose common cost shocks on competing firms, they can generate parallel price increases that are entirely consistent with competitive behavior while simultaneously creating conditions that may make coordination more attractive or easier to sustain. Drawing on recent empirical research on tariff incidence, pass-through,