Endogenous Technological Change in the DICE Model of Global Warming

在考虑气候变化等长期环境问题的解决方案时，重要的是要考虑技术变革可能发挥的作用。尽管如此，大多数气候变化的经济模型都认为技术是外生的。由于为应对气候变化而采取的政策可能会对技术变革的速度和方向产生很大影响，这些模型错过了政策和创新之间的重要联系。拟议的项目利用能源行业技术变化的经验结果，将内生技术变化纳入气候变化的DICE模型，以解决这一问题。到目前为止，很少有气候变化模型包括影响碳排放的内生技术变化。尽管这些模型对模拟内生技术变化的努力做出了宝贵的贡献，但它们的问题是缺乏对技术变化性质的经验估计。因此，拟议研究的最重要贡献是，它利用能源部门技术变化的经验研究，更准确地模拟可能有助于改善气候变化的技术变化。拟议研究将从修改气候变化的DICE模型开始，以与现有经验研究一致的方式包括内生技术变化。此外，通过使用DICE模型，该模型明确地模拟了温室气体减排的成本和收益，拟议的研究旨在更好地理解考虑内生技术变化如何影响最优政策决策。可以想象有两种抵消效应。首先，人们可能希望征收更高的碳税，因为碳税会增加研发，从而降低实现特定减排水平的成本。其次，可能需要更低的碳税，因为由税收引发的创新可以更容易地实现给定的减排目标。修改后的骰子模型将被用来研究这两种影响中的哪一种起主导作用。最后，拟议的研究通过模拟后备技术对开采可耗尽的化石燃料供应的影响，扩展了其他研究人员在该领域的先前工作。特别是，该项目询问，加快非碳后备技术技术进步的政策是否也会提高化石燃料库存的提取速度。

When considering solutions to long-term environmental problems such as climate change, it is important to consider the role that technological change may play. Nonetheless, most economic models of climate change treat technology as exogenous. Since policies adopted to combat climate change are likely to have a large impact on the pace and direction of technological change, these models miss the important link between policy and innovation. The proposed project addresses this concern by making use of empirical results on technological change in the energy industry to incorporate endogenous technological change into the DICE model of climate change.To date, few models of climate change include endogenous technological change that affects carbon emissions. Although these models offer valuable contributions to the efforts of modeling endogenous technological change, they suffer from a lack of empirical estimates on the nature of technological change. Thus, the most important contribution of the proposed research is that it makes use of empirical studies of technological change in the energy sector to more accurately model technological change that may help ameliorate climate change.The proposed research will begin by modifying the DICE model of climate change to include endogenous technological change in a manner consistent with existing empirical studies. In addition, by making use of the DICE model, which explicitly models both the costs and benefits of greenhouse gas reduction, the proposed research aims to provide a better understanding of how consideration of endogenous technological change affects the optimal policy decision. One can imagine two offsetting effects. First, a higher carbon tax may be desired, because the tax leads to increased R&D, which lowers the cost of achieving a given level of abatement. Second, a lower carbon tax may be desired, because the innovation induced by a tax allows a given abatement target to be achieved more easily. The revised DICE model will be used to study which of these two effects dominates.Finally, the proposed research extends previous work of other researchers in this area by modeling the effect of research on a backstop technology on the extraction of an exhaustible supply of fossil fuels. In particular, the project asks whether policies that speed up technological advances in non-carbon backstop technologies also increase the rate at which the stock of fossil fuels is extracted.