Testing for Factor Price Equality with Unobserved Differences in Factor Quality or Productivity
提出一种方法，在要素生产率存在未观测差异时识别相对要素价格均等化的偏离，利用美国170个地方劳动力市场1972、1992和2007年非生产与生产工人的相对工资数据，发现三年中相对工资均存在统计显著差异，且差异随时间增大并与产业结构相关。
We develop a method for identifying departures from relative factor price equality that is robust to unobserved variation in factor productivity. We implement this method using data on the relative wage bills of nonproduction and production workers across 170 local labor markets comprising the continental United States for 1972, 1992, and 2007. We find evidence of statistically significant differences in relative wages in all three years. These differences increase in magnitude over time and are related to industry structure in a manner that is consistent with neoclassical models of production.