题目：Optimal Dynamic Carbon Pricing under Firm Relocation
主讲人：Daniel Nachtigall 德国柏林自由大学经济系博士候选人
简介: In a dynamic setting, I analyze optimal carbon taxes when a country unilaterally implements climate policies. Carbon taxes induce firms to invest in abatement capital, but may also lead to relocation of some firms. The social planner addresses the relocation problem by offering firms transfers conditional on maintaining the production in the home country. I show that if transfer payments are only feasible in the near future (period 1), but not in the far future (period 2), it is optimal to implement a declining carbon price path with the first period carbon price exceeding the marginal environmental damage. The reason is that a high carbon price triggers more investments in abatement capital and, thus, creates a lock-in effect. Given that firms have invested much in abatement capital, they are less affected by carbon prices in the future and therefore less prone to relocate in the second period after transfer payments have ceased. If transfer payments involve some welfare costs, the social planner may not want to prevent all firms from relocating immediately. Then, the first period carbon price becomes a two-edged sword as it aggravates the relocation pressure in the first period, but also increases the lock-in effect and averts relocation in the second period. Depending on the size of both effects, the social planner optimally chooses either a low or a high carbon price.