Adopt or Innovate: Understanding technological responses to cap-and-trade

One important motivation for creating cap-and-trade programs for carbon emissions is the expectation that they will stimulate much-needed low-carbon innovation. I construct a new panel of British firms to investigate this hypothesis, finding that the European carbon market has encouraged greater low-carbon patenting and R&D spending among regulated firms, without necessarily driving short-term reductions in carbon intensity of output. This stands in contrast to past cap-and-trade programs, which have primarily spurred adoption of existing pollution control technologies, with little effect on innovation. I discuss how to reconcile these contrasting findings and implications for the future of carbon markets.

构建碳排放总量管制与交易（cap-and-trade）机制的一项核心动因，在于预期其能够刺激亟需的低碳创新。本文构建了全新的英国企业面板数据集以验证这一假说，研究发现欧洲碳市场推动了受规制企业增加低碳专利产出与研发投入，但并未必然推动产出碳强度的短期下降。这一结论与既往总量管制与交易机制的实践形成鲜明反差：过往此类机制主要推动了现有污染控制技术的采纳，对创新的影响微乎其微。本文还探讨了如何调和这些差异化的研究结论，以及其对碳市场未来发展的政策启示。