Tipping into protectionism: Tariff shocks and the fragility of free trade
构建了一个动态政治经济学模型，揭示关税冲击如何通过削弱竞争力，使经济从自由贸易永久滑向高关税低福利的保护主义均衡。
This paper develops a dynamic political-economy model of trade-policy hysteresis. Tariffs reduce innovation and competitiveness but generate short-run benefits for import-competing sectors, creating incentives for myopic policymakers to adopt protectionism. The interaction between myopic protectionist policy and slow-moving competitiveness generates two stable steady states: a low-tariff, high-competitiveness regime and a high-tariff, low-competitiveness regime. Although free trade is welfare superior, it is politically fragile. Temporary tariff shocks that sufficiently erode competitiveness can permanently shift political incentives toward protectionism, trapping the economy in a low-competitiveness equilibrium with persistently high tariffs and lower welfare.