中文摘要
本文认为，将物化技术纳入考量，极大地增加了资本在解释跨国农业劳动生产率差异中的重要性。为此，我们利用了一套新的农业资本价格数据集。我们记录到，无论按绝对值还是相对于旧资本，新资本在较富裕国家都更为昂贵。一个不同质量资本的内生采纳模型将这些价格差异与物化技术的演进路径联系起来。具体而言，我们的模型从新资本的价格中识别物化技术的水平，并从新资本相对于旧资本的价格中识别物化技术的增长率。随后，我们测量了处于不同发展阶段的16个样本国家的农业经质量调整的资本存量。我们发现，对质量差异进行调整几乎使资本在解释跨国农业劳动生产率差异中的重要性翻倍：从21%增至37%。此外，在过去25年中，资本质量的改善一直是农业劳动生产率增长的重要来源，分别解释了穷国和富国生产率增长的21%和35%。
Abstract
Abstract This article argues that accounting for capital-embodied technology greatly increases the importance of capital in explaining cross-country differences in agricultural labor productivity. To do so, we draw on a novel data set of agricultural capital prices. We document that new capital is more expensive in richer countries, both in absolute terms and relative to old capital. A model of endogenous adoption of capital of different quality links these price differences to the path of capital-embodied technology. In particular, our model recovers the level of embodied technology from the price of new capital and the growth rate of embodied technology from the price of new capital relative to old capital. We then measure the stocks of quality-adjusted capital in agriculture for a sample of 16 countries at different stages of development. We find that adjusting for differences in quality almost doubles the importance of capital in accounting for cross-country differences in agricultural labor productivity: from 21% to 37%. In addition, improvements in capital quality have been an important source of agricultural labor productivity growth over the past 25 years, accounting for 21% and 35% of the productivity growth in poor and rich countries, respectively.