Carbon Taxes, Path Dependency, and Directed Technical Change: Evidence from the Auto Industry
利用80个国家几十年的汽车行业专利数据，研究发现企业面对更高的含税燃油价格时，更倾向于清洁技术创新，且创新存在路径依赖。模拟了清洁技术超越污染技术所需的碳税增幅。
Can directed technical change be used to combat climate change? We construct new firm-level panel data on auto industry innovation distinguishing between "dirty" (internal combustion engine) and "clean" (e.g. electric and hybrid) patents across 80 countries over several decades. We show that firms tend to innovate relatively more in clean technologies when they face higher tax-inclusive fuel prices. Furthermore, there is path dependence in the type of innovation both from aggregate spillovers and from the firm's own innovation history. Using our model we simulate the increases in carbon taxes needed to allow clean to overtake dirty technologies.