International production fragmentation has generated and reallocated value added as well as CO2 emissions across economies. Prior studies have mainly focused on the embodied emissions or value added in trade. The evidence regarding the embodied emission intensity, and particularly the role of policies, however, remains sketchy. This paper investigates the role of trade and environmental policies in embodiment flows by combining input-output analysis and the gravity model of trade, covering 43 economies over 2000–2014. First, we derive the domestic carbon and value-added contents of bilateral exports in an input-output framework, and find a declining trend in emission intensity in exports. Second, we use the gravity model to examine the determinants of trends in both flows, and further infer the combined effects on intensity. The results show that an open trade policy can lower emission intensity in exports by facilitating the selection of products that are higher in value-added but less emission-intensive. Economies with more stringent environmental policies have a lower emission intensity in exports, but a higher emission intensity in their imports, which suggests carbon leakage. Effective global climate mitigation will require a closer look at the emission intensity in exports and collective action to address the detrimental effects of carbon leakage.

国际生产分散化产生并重新分配了各个经济体的附加值和二氧化碳排放量。先前的研究主要集中在贸易中的隐含排放或附加值。然而，关于隐含排放强度的证据，特别是政策的作用，仍然是粗略的。本文通过结合投入产出分析和贸易引力模型，研究贸易和环境政策在体现流中的作用，涵盖 2000-2014 年期间的 43 个经济体。首先，我们在投入产出框架下推导出双边出口的国内碳和增加值含量，发现出口排放强度呈下降趋势。其次，我们使用重力模型来检查两种流动趋势的决定因素，并进一步推断对强度的综合影响。结果表明，开放的贸易政策可以通过促进选择附加值较高但排放强度较低的产品来降低出口的排放强度。环境政策较严格的经济体出口排放强度较低，但进口排放强度较高，这表明存在碳泄漏。有效的全球气候减缓需要仔细研究出口的排放强度，并采取集体行动来解决碳泄漏的不利影响。这表明碳泄漏。有效的全球气候减缓需要仔细研究出口的排放强度，并采取集体行动来解决碳泄漏的不利影响。这表明碳泄漏。有效的全球气候减缓需要仔细研究出口的排放强度，并采取集体行动来解决碳泄漏的不利影响。