Curbing Carbon Emission: Is a Carbon Tax the Most Efficient Levy

About the ProjectThe objective of this research is to understand how different policy tools could expedite the transition toward a low-carbon economy in a cost-effective manner. This project takes a pragmatic approach to climate change policies, recognizing the need to balance the economic and environmental impacts of these policies. Ignoring the cost of these policies could not only create a substantial economic burden but also lead to a loss of social mandate. This is one of the greatest risks to the successful implementation of sound climate change policy, which by its nature requires clear and predictable government commitment over the long-term.Key PointsThe ambitious environmental objectives of the Paris Agreement imply that, in order to curb carbon emissions, all cost-effective policy options should be considered. These options include carbon taxes, probably the most popular fiscal tool for curbing emissions, and various other taxes on fossil fuels. This study uses Spanish data to assess what are the optimal taxes on oil, natural gas and coal from a welfare perspective, and compares them with a carbon tax in a general equilibrium context. The results of the analysis are as follows:Among their options for reducing CO2 emissions, policymakers may consider taxing coal heavily. Less punitive taxation of oil and natural gas could also form part of an optimal strategy.For maximum effectiveness, we found that any planned tax on oil should always be lower than the tax on natural gas, and still lower than that on coal. This counterintuitive result comes about because oil has the highest marginal economic productivity of the three fuels, though natural gas is the cleanest fossil fuel in terms of CO2 emissions. According to standard economic theory, the marginal economic productivity of any fossil fuel should be similar to international prices for it in competitive markets.Carbon tax has both advantages and disadvantages for policymakers. In the short run, the revenue collected would be higher from an optimal mixture of taxes on the various fossil fuels – but, in the longer term, higher taxes might be seen by taxpayers as unreasonable and could result in a loss of support for the environmental policies they are intended to underpin.

关于本项目
本研究的宗旨在于探究如何通过不同的政策工具以经济效益的方式加速向低碳经济的转型。该项目采取务实的方法对待气候变化政策，认识到平衡政策经济影响与环境影响之必要性。忽视政策成本不仅可能造成沉重的经济负担，还可能导致社会授权的丧失。这是确保良好气候变化政策成功实施所面临的最大风险之一，此类政策本质上要求政府在长期内作出明确且可预测的承诺。
关键点
《巴黎协定》雄心勃勃的环境目标意味着，为了遏制碳排放，应考虑所有成本效益的政策选择。这些选择包括碳税，这可能是遏制排放最受欢迎的财政工具，以及针对化石燃料的其他各种税收。本研究利用西班牙数据，从福利角度评估石油、天然气和煤炭的最优税收，并在一般均衡框架下与碳税进行比较。分析结果如下：
在减少二氧化碳排放的选项中，政策制定者可能考虑对煤炭征收重税。对石油和天然气的税收惩罚较低也可能成为最优策略的一部分。我们发现，为了达到最大效果，任何计划对石油征收的税应始终低于对天然气的税，且低于对煤炭的税。这一看似悖论的结果源于石油在这三种燃料中具有最高的边际经济生产力，尽管天然气在二氧化碳排放方面是三种燃料中最清洁的。根据标准经济理论，任何化石燃料的边际经济生产力应与竞争市场中的国际价格相似。碳税对政策制定者既有利又有弊。短期内，从对各种化石燃料税收的最优组合中收集的收益会更高，但长期来看，更高的税收可能会被纳税人视为不合理，并可能导致对支持环境政策的不支持。