Real Options–Based Approach for Valuation of Government Guarantees in Public–Private Partnerships

A fast and computationally efficient valuation tool assists governments involved in Public–Private Partnership (P3) projects to examine many contractual configurations and design a guarantee that minimizes cost and reasonably mitigates the risk. This paper presents a continuous stochastic process derived from the risk factor forecast, thereby providing a more realistic and flexible model. A new valuation approach is developed by using a finite-difference method based on this continuous stochastic process. In a numerical example with one risk factor, it is shown that this new valuation tool is 100 times faster than the existing simulation-based approach. Its superior speed presents the opportunity to examine different contractual configurations, and as a result, design a more cost effective guarantee contract. Exercise strategies are derived for a multiple-exercise (Australian) guarantees structure. This new approach can be used by a government to reserve budget for the guarantees. Finally, the continuous underlying random process and exercise strategy enable this method to value more complex guarantee structures.