Environmental Policy and Induced Technological Change: Evidence from Automobile Fuel Economy Regulations
利用1985-2004年日本汽车规格数据，通过双重差分法估计燃油经济性法规对技术进步的诱导效应，发现法规收紧使日本汽车燃油效率相对提升3-5%，相当于无法规时需4-7年才能实现的效果。
This paper investigates whether environmental or energy-efficiency regulations induce innovations in relevant technologies through focusing on the tightening of Japanese fuel economy regulations in the 1990s and the early 2000s. Unlike previous studies that analyze patent data, I use vehicle-level specification data for 1985–2004 to estimate whether regulatory pressure accelerated technological progress in fuel efficiency. I compare Japanese automakers with selected American and European automakers in a difference-in-differences framework. The estimation results provide strong evidence for induced technological change: conditional on other vehicle attributes and the production cost, the regulatory tightening induced at least a 3–5% improvement in the average Japanese vehicle’s fuel economy relative to a counterfactual case with no regulatory change, an effect which would have taken at least 4–7 years to be realized with no pressure from fuel economy regulations or fuel prices.