Does Directed Innovation Mitigate Climate Damage? Evidence from U.S. Agriculture
研究美国农业创新如何响应气候变化，发现自20世纪中期以来创新转向更易受极端温度影响的作物，并抵消了1960年以来20%的潜在农业土地价值损失，但到2100年只能抵消13%的预计损害。
Abstract This article studies how innovation reacts to climate change and shapes its economic impacts, focusing on U.S. agriculture. We show in a model that directed innovation can either mitigate or exacerbate climate change’s potential economic damage depending on the substitutability between new technology and favorable climatic conditions. To empirically investigate the technological response to climate change, we measure crop-specific exposure to damaging extreme temperatures and crop-specific innovation embodied in new variety releases and patents. We find that innovation has redirected since the mid-twentieth century toward crops with increasing exposure to extreme temperatures. Moreover, this effect is driven by types of agricultural technology most related to environmental adaptation. We next show that U.S. counties’ exposure to induced innovation significantly dampens the local economic damage from extreme temperatures. Combining these estimates with the model, we find that directed innovation has offset 20% of potential losses in U.S. agricultural land value due to damaging climate trends since 1960 and that innovation could offset 13% of projected damage by 2100. These findings highlight the vital importance, but incomplete effectiveness, of endogenous technological change as a source of adaptation to climate change.