Agricultural composition and labor productivity
研究发现，发展中国家与发达国家农业劳动生产率的巨大差距，很大程度上源于农业内部构成差异：随着经济发展和资本积累，劳动密集型农产品相对价格上升，推动土地和劳动力转向资本密集型农业，从而提高整体劳动生产率。
Labor productivity differences between developing and developed countries are much larger in agriculture than in non-agriculture. We show that differences in agricultural composition across countries explain a substantial part of these labor productivity differences. To this end, we group agricultural products into two sectors: capital-intensive and labor-intensive agriculture. As the economy develops and capital accumulates, the price of labor-intensive agricultural goods relative to capital-intensive agricultural goods increases. This price change drives a process of structural change that moves land and farmers to the capital-intensive sector, increasing labor productivity in agriculture. We illustrate this mechanism using a multisector growth model that generates transitional dynamics consistent with patterns of structural change observed in Brazil and also differences in agricultural composition and labor productivity consistent with cross-country data.