Optimized real options-based approach for government guarantees in PPP toll road projects

The uncertainty associated with future traffic levels in Build–Operate–Transfer toll road projects lead to difficulties in obtaining finance and thus to unsuccessful bids. In order to increase the attractiveness of projects for investors, governments usually provide several types of guarantees such as Minimum Revenue Guarantees (MRGs). In many cases, challenges associated with the valuation of this uncertainty force governments to provide excessive guarantees, placing an increased burden on the public budget. Based on this problem, a real-option-based model is presented for the identification of optimum upper and lower boundaries of compound MRG and Maximum Revenue Cap (MRC) options which establish a fair risk allocation structure. The proposed model uses an optimization approach in which high levels of guarantees in initial years are compensated by the transfer of excess revenues obtained by the private investor in late years. The optimum upper and lower boundaries of compound MRG and MRC options are identified using the proposed model. Results reveal that the emerging net guarantee amount generated by using any pair values of the MRG and MRC that remain in the identified interval not only maintains the attractiveness of project for private investors but also restrains government contingent liabilities. Thus, the identified interval of MRG and MRC enables the structuring of a flexible bargaining environment for both parties.