Although substantial studies have discussed drivers or determinants of eco-innovation including environmental policies, research on relations between public procurement and environmental innovation is rare. This paper applies the propensity score matching (PSM) method to estimate the impact of public procurement on enterprises’ decisions to introduce innovations with environmental benefits, with 2014 Community Innovation Survey (CIS) data collected from firms in 15 European countries. The findings suggest that companies with a public contract are 5.7% more likely to introduce innovations with environmental benefits. Furthermore, this paper estimates the effects perfectly matching the types of eco-innovation, firm size, cooperative partner, nations, and industrial sectors. The firms that provide goods or services to public sectors have a larger possibility to be innovative for recycled waste, water, and material for their own use or sale (by 3.3~4.5%); for reduced energy use and CO₂ footprint by end users (3.1~4.2%); for reduced air, water, noise, and soil pollution by end users (5.4~5.7%); for facilitated recycling of the product after use (2.6~3.4%); and for extended life length of the product (2.9~3.4%). The eco-innovation efforts in small (250 employees) companies are examined to be promoted by public procurement, with the magnitude of 5.0~6.3% and 7.5~10.6%, respectively. This study provides a creative theoretical framework of “dual-impetus” to explain the effect of public procurement on eco-innovation and is one of the first empirical research studies contributing to the discussions of the emerging topic by providing a more nuanced view of the heterogeneous effect of public procurement and companies’ eco-innovation behavior.

碳排放权交易政策是中国实现“双碳”目标的核心举措之一。以1998-2024年间中国知网的1268篇中文文献和Web of Science中的1306篇英文文献为样本，本文利用文献计量学方法梳理有关碳排放交易政策研究的发文趋势、被引表现及期刊分布，将高频关键词归纳为政策背景、政策机制、政策评估和政策协同四个类别展开分析，并借助CiteSpace绘制知识图谱，呈现机构合作网络、关键词共现与时区演进、研究热点检测及主题聚类结果。除“‘双碳’目标”外，“双重差分”、“绿色技术创新”和“电力市场”是中文文献的热点，“绿色创新”则是英文文献的热点。中外文献主题聚类的集群有所差异，但碳配额、碳价格、差分模型是两者共有的特征。最后，本文总结中国碳市场研究现状并提出未来可能的方向。