PFI計畫折現率訂定基準之初探

A Preliminary Study on Instructions of Discount Rate Setting for PFI Projects

姚沛妤(Pei-Yu Yau)

指導教授 ： 周慧瑜

朝陽科技大學/理工學院/營建工程系/碩士(2009年)

摘要

公共建設的投資由於具有帶動經濟發展的效果，往往是國家重大施政項目之一。新政府於民國2008年上任後所推動之愛台十二建設，即計畫於8年內投資新台幣3.99兆元，其中1.34兆元希望來自民間投資，約佔總投資金額的三分之一，如此龐大的民間投資目標，對應我國歷年促參案件之簽約金額，2004年簽約金額雖達1.307億元之多，後則逐年下降至2008年之168.5億元，由推案金額逐年萎縮的現象看來，我國現行著重自償性的促參體制，恐難充分提供民間參與各類型公共建設計畫。目前世界各國在公共建設與服務上所推動之民間參與模式，大致上可分為『特許權（concession）』與『PFI （Private Finance Initiative）』等兩大系統。前者即我國現行促參法所涵蓋之範疇，本文簡稱促參模式；而PFI模式則是由英國於1992年首先正式施行，且已廣泛應用於30多個國家，尤其用以推動公益性較強而自償性低之公共服務領域，推行至今普遍獲得了正面的效益評價。因此，是否將PFI作為我國推動公共建設與服務的下一條重要策略途徑，近年來也一直是我國政府主管單位持續評估的課題。
公共建設計畫因資金結構的不同，雖然同樣需進行經濟與財務等面向之可行性評估，但實際上各自之評估目的，存在有本質特性上的差異。本研究所針對之研究主體「折現率」，更因促參計畫往往年期較長，因此在進行投資效益分析時，其設定值之大小，對於評估結果會有更為顯著的影響。以目前國內公共建設計畫進行財務可行性評估之作法來看，即可發現目前折現率之訂定尚未有明確的計算準則或設定之依據，以致先期審議、決定計畫推動優先次序、乃至廠商競標時，均缺乏公平一致之比較基礎。具體言之，完全自償性之促參計畫中，既然民間需自行籌措經費，且收益也需由營運或附屬事業收入自行回收，在資本結構上即與一般民間投資計畫無異；此時折現率在財務評估中之意涵，較著重於投資報酬率的概念；但除此之外，其他需部分仰賴政府出∕投資之各類型促參計畫，或者以組合型促參模式推動之計畫，資金來源或多或少均包含公共預算之挹注，亦即來自社會大眾的稅收。尤其未來國內若欲推動PFI模式，民間對計畫資金僅在興建階段負責融資，但政府仍需於營運階段起依據民間提供之服務水準按合約對價給付服務費用，內涵即在於歸墊成本，並給予合理對應風險承擔度之利潤。因此就整體計畫而言，除非民間機構未提供符合要求之服務水準，否則政府仍是計畫的出資主體。因此在完全自償之促參計畫之外，折現率於計畫評估中所代表的意義，更應包含有社會大眾基於對未來公共投資所帶來效益的期待，亦即所謂的社會時間偏好（social time preference）。綜上所述，本研究由彙整國內目前在政府採購模式與促參模式下所使用之折現率訂定方式出發，針對PFI模式在資金結構上之差異特性與財務評估目的，收集並分析包含英國、澳洲、愛爾蘭等推動PFI模式較成熟國家之折現率訂定機制，分析其計算公式之合理性，與我國制度環境下機制導入之適用性，以綜整出對我國公共建設計畫評估中，關於折現率訂定機制之相關建議。
依循上述研究主軸，本研究對於我國未來如欲推動PFI模式時折現率之訂定基準，主張依照現有條件如資料可得性與政府組織權責等，建立循序漸進之策略作法。短期為求推動時效時，可參酌愛爾蘭及澳洲之折現率訂定基準，但均為條件式可行，若參酌愛爾蘭之作法我國必須先確認折現率訂定之權屬機關，若參酌澳洲之作法，則模式中之風險值，須以匯集專家經驗估計參數值的方式，解決缺乏案例數據提供統計值的問題；至於中長期而言，我國政府應正視過去公共建設專案之歷史案例缺乏系統性風險資訊管理的問題，儘速著手建立相關之資訊管理系統並確實貫徹執行機制，待累積足夠案例經驗後，即可仿照澳洲的作法，運用CAPM概念建立折現率計算模式，並由政府主管單位制訂作業規範力求各工程主辦機關在有明確設定基準的條件下，落實折現率訂定之一致性與合理性，進而對我國公共工程採購決策品質之提升有所助益。

關鍵字

民間參與公共建設 ； 折現率 ； PFI模式

並列摘要

Public investment in infrastructure has promotive effects on economic development. The i-Taiwan 12 Projects, being a new economic development blueprint for Taiwan, call for the investment of NTD3.99 trillion over eight years since 2008. However, NTD1.34 trillion, ie. about one-third of the total, is expected to contributed by the private sector. Compared with the annual cumulative contract prices of the private investment promotion projects from 2002 to 2008, such investment from the private sector should be a tough goal. The private participation model implemented in infrastructure and public service projects can be divided into two major systems: “concession model” and “PFI (Private Finance Initiative) model“. The concession model has been used in Taiwan with the promulgation of the Law for Promotion of Private Participation in Infrastructure Projects on 2000. The PFI model, first adopted by United Kingdomon 1992, has been introduced in more than 30 countries. It has not been applicable in Taiwan yet, but it is broadly regarded as positive to rapidly push ahead with the investment on infrastructure and public services, especially those with high public interests but low self-liquidity. Therefore, it is an important issue for Taiwan government to investigate how to introduce PFI model into domestic private participation system for social capital investment.
On the other hand, for each infrastructure or public service projects, either the economic or the financial feasibility assessment plays a key role in helping the public authorities to evaluate the value of the project and to choose the optimal procurement model. Depending on different capital structures under various procurement models, the projects should be analyzed by different principles, for example, the discount rate. The influence of the discount rate over the the results of project evaluation can be significant even to change the conclusion. However, there exists no standard for the calculation or setting of the discount rate, which means there is a lack of fair and consistent comparable basis among different projects or different proposals from bidders. For the above reason, this research first collected the current conditions of discount rate setting in various procurement systems from real cases, and found out the evidence of misusing the discount rate due to the absence of the setting rule. Then the study put the focus on how the discount rate should be set in PFI projects. The process and parameters of discount rate setting in England, Australia and Ireland are reviewed, and furthermore the domestic government structure and institutional environment are contrasted with the three countries. The findings from the comparison show that for the current structure of the domestic central government, the competent authority of PFI system could be a controversial issue, so that the responsibility of discount rate setting could not clearly be recognized as well. It might be the foremost problem facing the government as introducing PFI system into Taiwan.
Besides, According to the domestic institutional conditions, this research suggested short-term and long-term strategies for establishing the standards of discount rate setting. For short term, the way that Ireland government adopts might be applicable but not approapriate enough if without transparent setting course. On the other hand, although the procedure adopted by Australian government could not be duplicated in Taiwan for the absence of historical data collection about the risks and their consequenses in infrastructure projects, some parameters for calculating the discount rate could be substituted or estimated by experienced public agencies or experts in construction industry. For long term, through systematically cumulating historical data of PFI projects, this research regards that the CAPM model learned from Australian government could be reformed, and would be a reasonable method to set the discount rate for PFI projects.

並列關鍵字

Private Participation in Infrastructure Projects ； Discount Rate ； PFI Model

參考文獻

14.王治平、姜堯民，「民間參與公共建設財務評估模式規劃」，行政院公共工程委員會委託研究報告，臺北，2001。

18.行政院公共工程委員會網站，http://www.pcc.gov.tw，2009.03。

23.林貴貞，「民間參與公共建設案件營運績效評估機制之建置委託專案服務案-初步建議報告」，行政院公共工程委員會委託研究報告，臺北，2006。

31.黃玉霖，「各類型民間參與公共建設案件執行成效之調查與分析」，行政院公共工程委員會委託研究報告，臺北，2003。

3.HM Treasury, Green Book, HMSO, London, 2007a.