“…Public-private partnership (PPP) schemes have been widely applied worldwide in many fields, such as toll roads, water plants and energy infrastructure (e.g., Biygautane et al, 2019;Carbonara & Pellegrino, 2018Feng et al, 2015;Osei-Kyei & Chan, 2018;Song et al, 2015;Valipour et al, 2019;Villani et al, 2017). Despite the advantages of PPP arrangements, private investors are assuming great risks and uncertainties due to the large scale of investment and long payback period (Liu et al, 2014); consequently, they may often require mitigation of these risks through guarantees provided by governments to compensate for possible private losses (Carbonara & Pellegrino, 2018;Liu et al, 2019b;Pellegrino et al, 2019;Zapata Quimbayo et al, 2019).…”