The CCEP-BIT’s graduate student Kun ZHANG went to the State University of New York at Binghamton for a two-year joint PhD program at the end of November 2018. The foreign tutor is Professor Zili Yang, Department of Economics. Professor Yang is mainly engaged in resource and environmental economics, energy economics, economic modeling, and co-developed the most influential climate change integrated assessment model (RICE). Kun ZHANG’s research mainly focused on the cooperation issues of reducing emissions in response to climate change. His research work during the visit period are as follows:

　　First, based on different emission accounting principles, assess the provincial economic impact of carbon tax in China. Considering that under different accounting principles, the carbon emission responsibilities are often different. This work is based on China's multi-regional input-output model, considering the production-based and consumption-based principles, and analyzes the impact of carbon tax on the tax burden and sectoral competitiveness of China's provinces. The results show that under the scenario where carbon tax revenue is used to reduce production tax, developed regions such as Beijing, Shanghai, Zhejiang, and Jiangsu are net beneficiaries of carbon tax. On the contrary, recycling the tax revenues to low-income households makes the less-developed provinces in the central and western China become net revenue receivers. In addition, for competitiveness effects, the results show that, compared with the production-based principle, the carbon tax under the consumption-based principle could reduce the competitiveness effect of the more severely affected sectors in the less developed regions, while slightly increasing those effects in the developed provinces. Moreover, combined with the main regional development strategies, the specific suggestions are provided on feasible cooperation measures between regions (e.g. financial support, technology transfer). The research has been published in the Journal of Policy Modeling (SSCI).

　　Second, a comparative analysis of the impact of mechanisms that promote participation in climate mitigation: border carbon adjustment and uniform tariff measures. Effective reduction of greenhouse gas emissions and achievement of climate goals require international cooperation. As one of the largest carbon-emitting countries, the United States announced its withdrawal from the Paris Agreement in 2017, which has affected the ambition and confidence of countries to actively implement emission reduction policies. Therefore, in dealing with climate change, how to protect the interests of countries that implement emission reduction policies and how to promote non-cooperative countries to join the emission reduction coalition has always been a problem worthy of study. With the help of the C3IAM/GEEPA model, this research analyzes the impact of border carbon adjustment (BCA) and unified tariff measures under a unified framework. And under the scenario of uniform tariff measures, further consider two design schemes for determining uniform tariff rates, one is based on the principle of equal taxation and the other is equal carbon reduction targets. The results show that BCA is more effective in reducing US carbon leakage than the unified tariff mechanism. However, in terms of GDP loss and welfare loss, the unified tariff increases measures based on emission reduction targets will lead to greater loss of US GDP and welfare, which will be more conducive to promote the US to implement emission reduction policies. The research has been accepted by Climate Change Economics (SSCI).

　　Third, there is some work currently underway. Based on the RICE-China model, we hope to examine the impact of different cooperation measures between regions across the world on China's future energy demand. The RICE model is a global multi-regional integrated assessment model, but it does not consider the tailed energy structure in each region. This study further refines the modeling structure of the Chinese energy sector of the RICE model, incorporating different types of fossil energy and renewable energy. Therefore, it is possible for us to explore the influence of different cooperation measures between different regions of the world on China's future energy demand.

　　Finally, during the study visit, Kun ZHANG also participated in a series of environmental economics forums organized by the Department of Economics, listened to the researcher’s reports from different universities, such as the University of California, Berkeley, Cornell University, University of Illinois, and Arizona State University. He said he is very lucky and grateful to have this opportunity to study abroad. Because it not only broadened the research horizon, but also learned different research ideas and methods, which will be of great help for his future research work.