Trade and Productivity
研究发现国际贸易对生产率有显著正向影响，使用实际开放度（进出口占购买力平价GDP比重）作为贸易指标，并控制了制度质量和地理因素，同时处理了内生性问题。
We find that international trade has an economically significant and statistically robust positive effect on productivity. Our trade measure is imports plus exports relative to purchasing power parity GDP (real openness), which we argue is preferable on theoretical grounds to the nominal measure conventionally used. We also find a significantly positive aggregate scale effect. Our estimates control for proxies of institutional quality as well as geography and take into account the endogeneity of trade and institutional quality. Our analysis of the channels through which trade and scale affect productivity yields that they work through total factor productivity.