Climate policy and the optimal extraction of high‐ and low‐carbon fossil fuels
研究碳排放约束如何影响高碳（如煤）和低碳（如天然气）化石燃料的价格与开采时序，发现约束下可能转向更脏的燃料，且生产率比碳含量更重要。
Abstract. We study how restricting CO 2 emissions affects resource prices and depletion over time. We use a Hotelling‐style model with two non‐renewable fossil fuels that differ in their carbon content (e.g., coal and natural gas) and in addition are imperfect substitutes in final good production. We show that an economy facing a CO 2 flow‐constraint may substitute towards the relatively dirty input. As the economy tries to maximize output per unit of emissions it is not only carbon content that matters: productivity matters as well. With an announced constraint the economy first substitutes towards the less productive input such that more of the productive input is available when constrained. Preliminary empirical results suggest that it is cost‐effective to substitute away from dirty coal to cleaner oil or gas, but to substitute from natural gas towards the dirtier input oil.