Structural Transformation, the Mismeasurement of Productivity Growth, and the Cost Disease of Services
研究发现，工人按比较优势自选择进入行业，导致收缩的制造业与扩张的服务业报告的生产率增长差异可能源于劳动力质量变化，而非真实生产率差异。
If workers self-select into industries based upon their relative productivity in different tasks, and comparative advantage is aligned with absolute advantage, then the average efficacy of a sector's workforce will be negatively correlated with its employment share. This might explain the difference in the reported productivity growth of contracting goods and expanding services. Instrumenting with defense expenditures, I find the elasticity of worker efficacy with respect to employment shares is substantially negative, albeit estimated imprecisely. The estimates suggest that the view that goods and services have similar productivity growth rates is a plausible alternative characterization of growth in developed economies.