以賽局理論分析促進民間參與公共建設(PPP)制度之研究

Abstract

縱使公部門有良善的動機以促進民間參與公共建設（以下簡稱促參，而Build-Operate-Transfer(BOT)為其常見的一種方式）方式來執行公共建設，然而，個案的執行成果卻是良莠不齊。由於推動促參已是各國政府的趨勢，各國政府無不殷切想知道如何建立推動促參的適當制度，俾利成功地執行促參計畫。然而，與促參制度相關的研究有限，而且多是基於經驗法則。本研究即期透過更為嚴謹的研究方法，包括新制度經濟學、交易成本理論、賽局理論並結合個案研究，以提升促參相關制度研究的研究品質。本研究擇定兩個制度議題進行探討（「中央促參專責單位的角色」及「政府貸款保證契約的配套措施」），以展示所提出的研究方法具有可適切研究促參相關制度問題的價值，此外，該兩制度議題的研究成果，亦有助於提升促參的知識領域，以利執行公制合夥案件。 就中央促參專責單位的角色而言，屬於政策層面的制度議題。若其角色未事先釐清，中央促參推動單位將因此欠缺足夠的功能，難以適切的反映多變環境的需求，因此，這個組織就難以成功地推動促參案件。促參的活動，可以視為政府與私部門廠商間，彼此試著最大化各自利益的賽局，因此，依新制度經濟學，這組織的角色即可視為這個賽局的平衡解，雙方均會樂於維持這個平衡解。基此，本研究建立三個賽局情境以尋求對應的平衡解：單一主辦機關的單一賽局、單一主辦機關的重複賽局、政府（下含許多主辦機關）的重複賽局；此外，臺灣促參推動歷程及該國中央促參專責單位的角色演變，亦以個案研究的方式呈現。透過理論模型與個案研究的交互驗證，推論出該組織的共通角色為政府與民間廠商間信賴關係的創造者，是政府於促參案件的重複賽局中，為追求自身經濟效益最大化所建立的制度，以維護政府信譽，避免少數主辦機關於簽約後背棄夥伴關係的自利投機行為，引起民間廠商聯合抵制投標政府所有下屬主辦機關的案件，進而損及政府的總體長期利益。 而促參案件的契約條款，可視為個案層面的制度議題。政府在推動公私協力案件時，提供貸款保證是一個常見的措施，以促進私部門及金融機構的參與意願，雖然此舉可提高貸款可行性並降低貸款成本，然而，促參案件的成功機率卻會降低，這是因為專案公司的股東們，通常可透過參與初期的營建活動而獲取相當的利潤，當該利潤甚至超過其投入專案公司的股權時，此時，專案公司未來長期營運的好壞對其已相對不重要，因而欠缺對該案件的長期承諾。由以往政府提供貸款保證的促參案例經驗，由交易成本理論觀之，如果設計的契約機制未妥善管理民間廠商的投機行為，則政府的被挾持問題會更惡化。本部分的研究先進行個案分析，對象為臺北捷運場站聯合開發契約的協助融資機制，該協助融資機制具有類似政府貸款保證的特性，然而，亦設計許多配套機制，以保障臺北市政府的權益，而採用迄今，已有許多運用實例，可證其運用於該類案件的效果；基此，本研究進一步提出通案的政府貸款保證賽局模型，可運用於他類公共建設案件，分析建議政府得以本研究建立的模型，計算民間廠商應提供的自有資金比率外，並應確保金融機構於政府介入時仍要持續提供貸款，均為政府提供貸款保證的前提。 本研究提供決策者理論基礎與框架，以加速其執行促參案件的學習過程，而所探討的兩個制度議題，亦均具實用價值。此外，就營建領域的研究者而言，本研究結合新制度經濟學、交易成本理論、賽局理論及個案分析的研究方法，亦可運用於分析其他促進民間參與公共建設領域相關的制度議題。

Despite the good intentions for the public sector to use public-private partnerships (PPPs, a common form is Build-Operate-Transfer, BOT), results have been mixed. Together with the global expansion of PPP, governments around the world are keen to know how to establish proper institutions in order to promote PPP programs successfully. However, relevant research is limited and mainly based on rule-of-thumbs. This study aims to improve the quality of PPP research related to institutional issues by a more rigorous way which includes New Institutional Economics (NIE), Transaction Cost Theory (TCE), Game Theory and case study. Two institutional issues, the role of national PPP units and proactive measures of governmental debt guarantees, are selected to demonstrate the value of the proposed research methodology in conducting institution-related research. In addition, the findings of each topic can advance the body of knowledge in PPP implementation. Regarding the role of national PPP units, it is a policy-level institution. Unless its role is clarified, a national PPP unit cannot be successful because it lacks adequate authority to respond appropriately to the changing environment. The PPP activities can be analyzed as a game between the host government and private developers trying to maximize their respective payoffs; thus, in accordance with NIE, a national PPP unit can be considered an endogenous equilibrium outcome of a game. On the basis of this perspective, three game theoretical models are constructed to find equilibriums: a single game for a single authority, repeated games for a single authority, and repeated games for government with multiple subordinate authorities. This part also uses a case study to present the history of PPPs in Taiwan and the evolutionary role of the National PPP Taskforce, Taiwan. National and international data confirm the theoretical model, which indicates that the common role of a national PPP unit is as a trust-creator between the public and private sectors. The contractual arrangement in a PPP contract can be viewed as the project-level institution. Governmental Debt Guarantees (GDGs) are often used to encourage involvement by developers and financial institutions in PPP projects. However, even after demonstrating the bankability of a project and reducing debt cost, the success of the project may be prevented by the lack of long-term commitment from shareholders. Equity contributions by developers in the project company are generally recovered from earnings on short-term construction activities. Based on lesson learned from early PPP projects with GDG, the hold-up problem for government in the view of TCE theory may worsen if the designed contractual structure does not adequately manage opportunistic behaviors from developers. This part empirically examined the effects of a structured GDG mechanism with particular complementary measures applied in joint projects to develop the Taipei Mass Rapid Transit (MRT) stations. A GDG game model was then applied to bridge the theoretical gap based on the Taipei MRT experience. The analysis shows that requiring the developer to provide sufficient equity and ensuring the commitment of the lender to provide the loan are the appropriate proactive measures. This pilot study contributes to the theoretical foundation that policymakers need to accelerate the learning process for implementing a PPP. It also provides researchers in the construction field with a more rigorous methodology by combining NIE, TCE, game theory and case study for analyzing other governance structures in the construction field.