Does Import Competition Force Efficient Production?
利用1975-1987年美国94个制造业行业的面板数据，发现进口竞争显著提高了高集中度行业的劳动生产率增长，但对低集中度行业无显著影响，且该效应存在一期滞后。
Increases in import competition led to large increases in labor productivity growth in highly concentrated industries during the period from 1975 through 1987. The finding is based on a panel of ninety-four manufacturing industries observed over four periods, each of three years duration. Imports had no observable effects on productivity growth in less concentrated industries; the strong effects in concentrated industries did not occur contemporaneously but appeared with a one-period lag. The effects are weakened but still statistically significant when Bureau of Labor Statistics productivity data are replaced by National Bureau of Economic Research data and in a larger panel with less precise trade data. Copyright 1994 by MIT Press.