民間參與重大交通建設風險分擔之研究－營收風險

Abstract

本研究主要的目的是為解決促進民間參與公共建設法第十一條第一項第五款有關風險分擔的課題，提出一套針對重大交通建設營收風險的分擔方式與量化營收風險貨幣化價值的方法。 本研究首先是以數學規劃法，根據政府及民間機構兩個主體所關心的不同課題進行分析；本模式的目標式是民間追求保證營收與實際營收的差距最大化（換句話說，就是最小化民間的營收風險），限制式是(1)受政府可用預算限制；(2)引入經濟上停業點觀念；(3)未來實際運量比保證運量低；(4)保證運量小於等於維持財務可行的最小運量；(5)保證運量大於零。模式整體的目的是要求解運量保證門檻值。 在模式求解之前，本研究應用其他規劃報告之運輸需求結果，瞭解各解釋變數與被解釋變數間的關係，以蒙地卡羅法模擬未來運輸需求的可能機率分配函數，將模擬出來的機率分配函數套入數學規劃模式當中，設定政府分擔營收風險的比例及政府的預算大小，進行模式門檻值的求解，本模式可計算出營收風險的貨幣化價值及運量保證門檻值。 最後，本研究以台北至中正機場捷運線為例進行個案分析，研究結果顯示模擬出的未來運量機率分配函數經過K-S檢定後服從Gumbel分配，將之套入模式中進行求解所得結果分析發現，當未來悲觀運量約4萬人次/每日時，總營收風險的價值約56億元；當未來悲觀運量約5萬人次/每日時，總營收風險的價值約45億元；當未來悲觀運量約6萬人次/每日時，總營收風險的價值約32億元。本研究最終將會提供政府及民間談判營收風險分擔方式的參考表，政府及民間可以依照各自對營收風險的承擔能力進行協商與談判，依據參考表將所得的分擔方式明訂於投資契約之中，以符合促參法第十一條的要求。

The purpose of this paper is to solve risk-sharing problem stipulated in the Act of Enhance Private Investment. It will bring up a methodology determining on operating revenue risk sharing proportion and quantifying its monetary value in the mega-transportation infrastructure. As well as to probe into what characteristics of transportation infrastructures the government should give private sector preferential treasures, and how to decide the guaranteed ridership threshold. Initially, according to government and private separate points of view, this paper employs mathematical planning approach to combine these two parts. Create a synthetic point of view as to achieve the considerations of both sectors. The object of synthetic model is to maximum the difference between guaranteed and real operating revenue (in other words, minimum private operating revenue risk). Subject to (1) Gov. budget constrain;(2) citing shut-down point theory;(3) future ridership must be smaller than guaranteed one;(4) guaranteed ridership must be smaller or equal to minimum ridership which can maintain feasible finance condition;(5) guaranteed ridership must be larger than zero; the purpose of this mathematical model is to solve guaranteed ridership threshold. Before solving the model, this paper uses Monte Carlo Simulation to simulate the future ridership possible probability density function (p.d.f.). In terms of this p.d.f., this paper assumes two parameters in advance, the proportion of Gov. risk share and the amount of Gov. budget, to determine the guaranteed ridership threshold. With regard to this model, executives also can determine operating revenue risk sharing proportion and quantify its monetary value. As well as this paper calculates both of government and private sector should defray the amount of deficit under the insufficient ridership condition in the future. Furthermore, this paper employs Taipei-C.K.S. MRT for example. The result reveals that the p.d.f. would obey Gumbel distribution via K-S test. If future pessimistic ridership were 40,000 per day, the total risk monetary value would be around 5.6 billions. If future pessimistic ridership were 50,000 per day, the total risk monetary value would be around 4.5 billions. If future pessimistic ridership were 60,000 per day, the total risk monetary value would be around 3.2 billions. Last of all, this paper will provide the operating revenue risk-sharing table that can be adapted during the negotiation between two sectors above. The executives could agree on the compromise result in the investment contract to conform to the requirement of Act of Enhance Private Investment.