The Likely Micro- and Macro-Economic Consequences of a Unilateral US Trade Policy

This paper examines the likely economic consequences of a unilateral US trade policy, particularly those involving across-the-board tariffs and retreat from multilateral commitments. Drawing on computable general equilibrium (CGE) models, dynamic macroeconomic frameworks, and a rich body of empirical literature, the paper demonstrates that the static efficiency losses, estimated by standard trade models, understate the true costs of protectionism. It identifies five key amplification channels – loss of economies of scale, supply chain fragility, diminished technological spillovers, investment hold-up under policy uncertainty, and financial market reactions – that interact to depress both short-run output and long-run growth potential. The analysis estimates that comprehensive unilateral trade measures could reduce US GDP by 2–3% in the short term and lower the long-term growth trajectory by 0.4–0.7 percentage points annually. While some strategic interventions may yield resilience or national security benefits, the paper concludes that unilateralism generates systemic economic risks and should be approached with caution. The findings underscore the need for integrated policy frameworks that combine targeted trade tools with domestic support and international cooperation.