This paper empirically examines the effect of the U.S. Corporate Average Fuel Economy (CAFE) standards on the technological progress in automobile fuel efficiency. Using detailed vehicle attributes data from 1978 through 2018, we find that more stringent fuel economy standards increase the rate of technological improvements in new passenger cars, and this effect is primarily driven by the response of U.S. automakers. We do not find evidence that CAFE standards have a similar effect on the technical change in light-duty trucks. Our results also indicate that higher gasoline prices have a significant and positive effect on the improvement of fuel-saving technology in both passenger cars and light trucks. Using our empirical estimates, we project that the recent rollback of Obama-era CAFE standards would forego an approximately 2-percent increase in cars’ fuel economy over the 2021–2025 period as a result of technological progress.

本文从经验上考察了美国公司平均燃油经济性（CAFE）标准对汽车燃油效率技术进步的影响。使用1978年至2018年的详细车辆属性数据，我们发现更严格的燃油经济性标准提高了新乘用车的技术改进率，而这种影响主要是由美国汽车制造商的反应所驱动。我们找不到证据表明CAFE标准对轻型卡车的技术变化具有类似的影响。我们的结果还表明，汽油价格上涨对乘用车和轻型卡车的节油技术的改进具有重大而积极的影响。使用我们的经验估计