Agricultural policy and productivity: evidence from Brazilian censuses
利用巴西几十年间的人口普查数据，研究发现技术进步年均4.5%，但平均生产者与前沿差距拉大，导致全要素生产率年均仅增长2.6%；公共科研拉大差距，而信贷、教育和道路建设政策则缩小差距。
Abstract Brazil's economic strategy has shifted hesitatingly during the last several decades from one of producer protection to trade competitiveness. Exploiting the variations these shifts have afforded, we use a sequence of decennial agricultural censuses to examine Brazilian policy implications for agricultural competitiveness and efficiency. Total factor productivity is decomposed into best‐technology and efficiency elements, each subject to policy influence. We find technology growth, at 4.5% per annum, to have been extraordinarily high, particularly in the south. But because productivity among average producers has fallen rapidly behind that on the technical frontier, total productivity growth has been a much more modest 2.6% per year. Public agricultural research programs most benefit the country's technological leaders, widening the gap between frontier and average producer. Credit, education, and road construction policies instead narrow that gap. Credit and road programs especially enhance efficiency in the south, where efficiency losses have been greatest.