PURPOSES : This study aims to analyze the impact of demand risk on two public-private partnership (PPP) projects, namely BTO and BTO-a. The main aspects covered in this study are: i) identification of key risk issues considering the structure of PPP projects, and ii) game theory-oriented scenario building and simulation of demand risk allocation from participants’ perspectives. METHODS : Using the institutional analysis and development (hereafter IAD) framework, a hypothetical structure is formulated to examine the interactions of demand risk. It develops a series of demand risk allocation models for PPP projects (i.e., BTO and BTO-a). The risk structures from the IAD step are the demand risk allocation issues. Using game theory-oriented simulation, this study evaluates demand risk based on scenario building. RESULTS : First, this study highlights the imbalanced rate problems of returns between the BTO and BTO-a projects proposed by the market. This may lead to improvement measures geared towards problematic methods for determining the rate of return among domestic PPP projects. Second, compared with the BTO type, this study expects that the BTO-a type may exhibit more effectiveness, which can increase the probability of project success in both the public and private sectors. Third, judging from game-theory-oriented approaches, this study confirms the function of the BTO-a as a method to adjust moral hazard in the private sector. CONCLUSIONS : Government management standards for BTO-a projects were derived based on the simulation results. It is necessary to select an appropriate project method based on rationality by balancing the IRR for each project method. Legal regulations should be applied separately to each part of the government guarantee. In addition, this study emphasizes that the introduction of ex-post value-for-money (VFM) analysis is essential for the efficient management of government expenses.

Since 'The Act on Private Investment of The Infrastructure' was established in 1994, private investment as well as government's investment in transport infrastructure has been active. However investment in transport infrastructure has more risks than others' due to uncertainty both in traffic volume and in construction cost. In the current appraisal procedure of deciding transportation infrastructure investment, instead of risk management, the sensitivity analysis considering only the changes of benefit, cost and social discount rate which are main factor affecting economic feasibility is carried out. Therefore the uncertainty of various factors affecting demand, cost and benefit are not considered in feasibility study. In this study the problems in current investment appraisal system were reviewed. Using Delphi technique the major factors which have high uncertainty in feasibility study were surveyed and then improvement plan was suggested in the respective of classic 4 step demand forecasting method. The range estimation technique was also mentioned to deal with the uncertainty of the future.