Journal of Economic Perspectives · 2026 · Miguel Acosta、Lydia Cox、Andrew Greenland、John Lopresti、Christopher M. Meissner、Martin Rotemberg
Abstract
We use a newly assembled, tariff-line-level dataset spanning the full history of US trade policy to revisit the evolution of tariffs since 1789. We document the institutional shift from Congressional setting to multilateral negotiation, the steady growth in granularity of the tariff code alongside expanding administrative capacity, and the under-appreciated role of specific tariffs, which feature prominently throughout US history and whose ad valorem equivalent moves mechanically with prices. We discuss the implications of this relationship for how we interpret past liberalization episodes and for empirical identification of tariff effects. Finally, we outline how the new data can advance research on the political economy of tariff-setting and on the macroeconomic and distributional consequences of trade policy.