ON THE OUTPUT EFFECTS OF BARRIERS TO TRADE*
通过将赫克歇尔-俄林贸易模型融入最优增长框架，研究贸易政策对宏观经济的影响，发现更开放的经济体具有更高的要素生产率，且存在选择性发展陷阱，贸易壁垒的增加会降低陷阱中的收入水平，从而有助于解释各国人均收入的差异。
We study the macroeconomic effects of international trade policy by integrating a Hecksher–Ohlin trade model into an optimal‐growth framework. The model predicts that a more open economy will have higher factor productivity. Furthermore, there is a “selective development trap” to which countries may or may not converge, depending on policy. Income at the development trap falls as trade barriers increase. Hence, cross‐country differences in barriers to trade may help explain the dispersion of per capita income observed across countries. The effects are quantified, and we show that protectionism can explain a relevant fraction of TFP and long‐run income differentials across countries.