Summary:
Green finance serves green investment, which serves the green economy. In practice, there is a huge demand for funds to develop green finance and promote environmental protection. In addition, it is unsustainable to rely solely on government financial support. Therefore, an important solution for this problem is public-private partnerships (PPP), in which the government and enterprises work together. However, enterprises are not enthusiastic participants of pollution prevention, green, and low-carbon PPP projects because they generally experience problems such as high investment thresholds, competition homogeneity, and high market risk. Although the direction of the new incentive method is clear, relying only on the traditional PPP contract framework is insufficient to manage the complex problems that arise when managing project portfolios. Thus, the contract model for traditional single-commercial PPP projects cannot be directly adopted. The key issues involved in the green PPP project portfolio are as follows: What elements must be considered when concluding the contract？ What coordination mechanism must be selected to ensure that the contract is signed？ Is there an optimal concession period for green PPP projects？ Is the green PPP project portfolio better than the traditional incentive mechanisms of direct government subsidies？ Exploring these issues will provide a good theoretical basis and technical support for the promotion and implementation of the combination of green PPP and high-yield projects. This paper uses the net present value method to propose a decision-making model for the optimal concession period of green PPP project portfolios based on the win-win goal of economic and environmental benefits. Our model differs from those of the literature in three dimensions. First, we introduce environmental benefits and extend the optimal concession period model for a single PPP project to the green PPP project portfolio. The goals of combining green PPP and high-yield projects include social welfare, environmental benefits, consumer surplus, and economic profits of enterprises and the government. Second, we compare the different game modes between the government and the enterprises, demonstrate the existence of an equilibrium, reveal the internal logic and key determinants of the optimal concession period, and provide a basic framework for the contract design of the green PPP project portfolio. Third, through a scenario analysis, we show the superiority of the green PPP project portfolio over the traditional incentive mechanism of direct government subsidies. The results provide theoretical support for promoting the combination of green PPP and high-yield projects. We obtain three important results. First, the combination of green PPP and high-yield projects can improve enterprise profits and stimulate social capital to participate in environmental governance and deal with environmental risks. Second, whether the government-enterprise contract can be signed successfully depends on the game decision-making mode. If the decision is made independently, although the concession period that maximizes enterprise profits can also achieve the highest environmental benefits, the game results are shown as “equilibrium on the edge” and it is difficult for both parties to enter into a contract. Therefore, it is necessary to study the behavioral restraint mechanism to promote coordination and cooperation between the government and enterprises. PPP stakeholders can then decide from a global optimal perspective and achieve a win-win situation of mutual economic profit and environmental protection. Third, compared with direct government subsidies, the combination of green PPP and high-yield projects not only increases consumer surplus and improves social welfare, but also copes better with the fisical burden. Therefore, policy guidance could be strengthened to manage the reasonable bundling of projects with strong correlation, upstream and downstream links, or adjacent sub-projects. Some direct government subsidies will gradually be replaced by the combination of green PPP and high-yield projects. The diversified funds can then be used to provide continuous support for environmental protection, achieve the goals of emission peak and carbon neutrality, and better serve the green economy and sustainable development.
魏晓云, 韩立岩. 绿色PPP项目组合的最优契约:经济与环境效应的福利视角[J]. 金融研究, 2022, 501(3): 60-78.
WEI Xiaoyun, HAN Liyan. The Optimal Contract for Green PPP Project Portfolios: A Welfare Perspective for Economic and Environmental Effects. Journal of Financial Research, 2022, 501(3): 60-78.
[1]曹启龙、盛昭瀚、周晶和刘慧敏,2016,《公平偏好下PPP项目多任务激励问题研究》,《预测》第 1期,第75～80页。 [2]陈国进、丁赛杰、赵向琴和蒋晓宇,2021,《中国绿色金融政策、融资成本与企业绿色转型——基于央行担保品政策视角》,《金融研究》第12期,第75～95页。 [3]高颖、张水波和冯卓,2014,《不完全合约下PPP项目的运营期延长决策机制》,《管理科学学报》第 2期,第48～57+94页。 [4]罗煜、王芳和陈熙, 2017, 《制度质量和国际金融机构如何影响PPP项目的成效——基于“一带一路”46国经验数据的研究》, 《金融研究》第4期, 第61～77页。 [5]吕萍、李晴和宋吟秋,2015,《考虑运营成本的收费公路Pareto有效BOT合同决策》,《系统工程理论与实践》第 7期,第1808～1815页。 [6]宋金波、王若宇和宋丹荣,2014,《高速公路BOT项目特许期决策模型》,《系统工程》第 2期,第91～97页。 [7]苏冬蔚和连莉莉, 2018, 《绿色信贷是否影响重污染企业的投融资行为？》, 《金融研究》第12期, 第123～137页。 [8]孙国峰、尹航和柴航,2017,《全局最优视角下的货币政策国际协调》,《金融研究》第3期, 第54～71页。 [9]王遥、潘冬阳、彭俞超和梁希, 2019, 《基于DSGE模型的绿色信贷激励政策研究》, 《金融研究》第11期, 第1～18页。 [10]文书洋、张琳和刘锡良,2021,《我们为什么需要绿色金融？——从全球经验事实到基于经济增长框架的理论解释》,《金融研究》第12期,第20～37页。 [11]燕雪、徐媛、盛昭瀚、王歌和徐峰,2017,《不同合作状态下交通特许经营项目特许期决策模型》,《中国管理科学》第 11期,第103～110页。 [12]杨晓冬和张家玉, 2019, 《既有建筑绿色改造的PPP模式研究:演化博弈视角》, 《中国软科学》第3期,第183～192页。 [13]周永圣、梁淑慧、刘淑芹和王珏, 2017,《绿色信贷视角下建立绿色供应链的博弈研究》, 《管理科学学报》第12期,第87～98页。 [14]An, X., H. Li, L. Wang, Z. Wang, J. Ding, and Y. Cao. 2018. “Compensation Mechanism for Urban Water Environment Treatment PPP Project in China” ,Journal of Cleaner Production, 201: 246～253. [15]Bao, H., Y. Peng, J. H. Ablanedo-Rosas, and H. Gao. 2015. “An Alternative Incomplete Information Bargaining Model for Identifying the Reasonable Concession Period of a BOT Project”, International Journal of Project Management, 33(5):1151～1159. [16]Chen, A., and K. Subprasom. 2007. “Analysis of Regulation and Policy of Private Toll Roads in a Build-Operate-Transfer Scheme under Demand Uncertainty”, Transportation Research Part A: Policy and Practice, 41(6):537～558. [17]Jin, H., S. Liu, J. Sun, and C. Liu. 2021. “Determining Concession Periods and Minimum Revenue Guarantees in Public-Private-Partnership Agreements”, European Journal of Operational Research, 291(2): 512-524. [18]Khanzadi, M., F. Nasirzadeh, and M. Alipour. 2012. “Integrating System Dynamics and Fuzzy Logic Modeling to Determine Concession Period in BOT Projects”, Automation in Construction, 22:368～376. [19]Ngee, L., R. L. Tiong, and J. Alum. 1997. “Automated Approach to Negotiation of BOT Contracts”, Journal of Computing in Civil Engineering, 11(2):121～128. [20]Shen, L., H. Bao, Y. Wu, and W. Lu. 2007. “Using Bargaining-Game Theory for Negotiating Concession Period for BOT-Type Contract”, Journal of Construction Engineering and Management, 133(5):385～392. [21]Shen, L., H. Li, and Q. Li. 2002. “Alternative Concession Model for Build Operate Transfer Contract Projects” ,Journal of Construction Engineering and Management, 128(4):326～330. [22]Wang, F., M. Xiong, B. Niu, and X. Zhuo. 2018. “Impact of Government Subsidy on BOT Contract Design: Price, Demand, and Concession Period”, Transportation Research Part B: Methodological, 110: 137～159. [23]Wang, Y., and J. Liu. 2015. “Evaluation of the Excess Revenue Sharing Ratio in PPP Projects Using Principal-Agent Models”, International Journal of Project Management, 33(6):1317～1324. [24]Wu, Y., C. Xu, L. Li, Y. Wang, K. Chen, and R. Xu. 2018. “A Risk Assessment Framework of PPP Waste-to-Energy Incineration Projects in China under 2-Dimension Linguistic Environment”, Journal of Cleaner Production, 183:602～617. [25]Xu, Y., C. Sun, M. J. Skibniewski, A. P. Chan, J. F. Yeung, and H. Cheng. 2012. “System Dynamics (SD)-Based Concession Pricing Model for PPP Highway Projects”, International Journal of Project Management, 30(2):240～251. [26]Xue, Y., and G. Wang. 2020. “Analyzing the Evolution of Cooperation among Different Parties in River Water Environment Comprehensive Treatment Public-Private Partnership Projects of China”, Journal of Cleaner Production, 270: 1-14. [27]Ye, S., and R. L. Tiong. 2003. “The Effect of Concession Period Design on Completion Risk Management of BOT Projects”, Construction Management and Economics, 21(5):471～482. [28]Zhang, X. 2011. “Web-Based Concession Period Analysis System”, Expert Systems with Applications, 38(11):13532～13542. [29]Zhang, X., H. Bao, H. Wang, and M. Skitmore. 2016. “A Model for Determining the Optimal Project Life Span and Concession Period of BOT Projects”, International Journal of Project Management, 34(3):523～532. [30]Zhang, Y., Z. Feng, and S. Zhang. 2018. “The Effects of Concession Period Structures on BOT Road Contracts”, Transportation Research Part A: Policy and Practice, 107:106～125.
