A strategic options game approach to support PPP investment decisions under risk-sharing mechanisms
结合博弈论和实物期权方法，建立数学模型评估PPP项目中的风险分担机制（如最低收入保障和收入上限），并应用于污水处理项目案例，帮助政府和投资者优化投资决策。
Abstract The need to obtain financial funds to pursue public utility investments implies the generation of Public-Private Partnership (PPP) projects. The PPP framework can involve risk-sharing mechanisms between public administration and private sector to encourage private investors to fund these projects. However, these risk-sharing mechanisms, such as Minimum Revenue Guarantee or Revenue Cap (RC), could generate opportunistic behaviors. For this reason, we can set this problem as a game in which government and private investors would act as players. This paper proposes a mathematical model to evaluate the PPP projects through a combination of Game Theory (GT) and Real Options Approach (ROA). The ROA is needed to price the uncertainty that affects PPP investments, and the GT captures the strategic interactions between public and private sectors. A case study on a wastewater treatment project is developed to apply the model we proposed.