The economic analysis of law for construction assessment system

在營造市場中，由於業主與營造廠之間存在嚴重的訊息不對稱現象，使得工程績效（包含品質、工期、安全等）與價格之間不易產生相應的對價關係（trade off），這不僅對市場競爭機制有負面的影響，而且品質不良的工程亦威脅著民眾的生命財產。顯然訊息不對稱是這些問題的根源，因此解決問題的對策即為降低訊息不對稱的程度。適逢此時營造業法明定營造業得定期評鑑，其目的在於揭露廠商的履約能力及施工品質水準，摒除達不到業主需求的廠商。當摒除最差的廠商後，工程績效與價格之間的對價落差就變小了，形同減緩上述問題的嚴重程度。 過去對評鑑制度的研究均著重於評鑑項目及權重的選擇，其主要的精神在於如何準確地描述廠商的能力，卻未考慮經濟環境、法令規定對評鑑分級的影響；也未考慮執行評鑑所需的時間、人力等限制對評鑑架構的影響。最新版的「營造業評鑑辦法草案」已經考慮執行層面的限制，因此本研究在草案的基礎上，考慮經濟、法令變動對廠商的報酬影響，並依據營造產業的實際狀況做合理的簡化，推論出廠商的報酬函數。接著本研究導入訊息經濟學中的傳訊賽局、篩選賽局理論，建構出評鑑分級的分析模型。此外，本研究更模擬法令規定、經濟環境變動的各種情境，以瞭解對這些變動對分級制度的影響趨勢。並根據情境模擬的結果，對評鑑制度提出改善策略，以有效達到區分廠商優劣的目的。 研究結果顯示，只要考量廠商的升級成本與利潤之關係，依此決定評鑑得分標準及分級標準，則評鑑結果可當成是廠商能力的“訊號”，那麼業主可以據此判斷營造廠能力之優劣。因此評鑑制度就形同能夠有效揭露營造廠能力優劣的訊息，再配合適當的獎優懲劣機制，就可以產生工程績效與價格間的對價關係，使不同能力的廠商都能夠獲得相應程度的利潤。這不僅提供廠商一個良性的競爭環境，同時也降低工程業主及使用者所承擔之風險。Due to the asymmetric information between owners and contractors, it’s difficult to trade off between performance (includes quality, duration, safety et.) and price in construction industry. This situation not only has negative influence on the market mechanism but also threatens public secure and life. Obviously, the origins of these problems are caused by the information asymmetry. Therefore, reducing the level of information asymmetry is a key point for solving the problems. Currently, the construction industry law proclaims each contractor has to take regular assessment. The purpose of assessment is to disclose the ability to execute one's contract and quality of projects. The public and private owners can discriminate a good firm from a bad one by the outcome of the classification, and exclude unqualified contractors. If do so, the gap between quality and price was narrowed which means the problem has eased. The former study focused on the items of assessment and weighted options. That essence is how to precisely describe the ability of contractors, however, does not consider the economic environment and the laws which influence the assessment system. It does not consider the execution time and the limitation of man-hours, either. The latest edition of regulation of classification of contractor (draft) already considered the limit of the enforcing aspect. Therefore, the study considers the reword-effect influenced by the variation of economics and laws use draft as the foundation. It infers the payoff function of contractors according to the reasonable simplification of real situation of the construction industry. Furthermore, this research recommends signaling games and screening games of information economics to establish the analysis model of assessment system. This study also simulates the laws and the varied circumstances of economic environment to understand the effect trend of classification system. And according to the result of scenarios simulation, this article presents some strategies for improvement of the assessment system in order to classify the layer of constructions efficaciously. The outcome of the study shows that the classification will provide a meaningful signal for the owners to judge contractors abilities without discrimination, if the relationship between the upgrade cost and the profit will be taken into consideration. The effect of assessment system does not include the ability of firms though. If an appropriate system of reward and penalties established, the market power will produce the relationship between performance and price. Then the system enables each firm to make a profit correspond to its ability. Consequently it will provide a benign competition environment and reduce the risk of owners and consumers.摘要 i Abstract ii 目錄 iii 圖目錄 v 表目錄 vii 第1章 緒論 1 1.1 研究動機 1 1.2 研究目的 3 1.3 研究範圍與限制 3 1.4 研究方法 4 1.5 研究流程 5 第2章 文獻回顧 7 2.1 營造業評鑑制度分類與分級概況 7 2.1.1 營造業評鑑制度分類 7 2.1.2 現行評鑑制度 10 2.1.3 過去與評鑑相關之研究 13 2.2 與本研究相關之逆選擇問題回顧 16 2.2.1 不對稱訊息之逆選擇問題 16 2.2.2 傳訊賽局（Signaling Games） 18 2.2.3 篩選賽局（Screening Games） 20 2.2.4 均衡類型 21 2.3 與本研究相關之賽局理論回顧 22 2.3.1 不完全訊息動態賽局 22 2.3.2 均衡穩定分析準則 23 第3章 傳訊賽局模型 25 3.1 模型假設與建立 25 3.1.1 評鑑制度傳訊賽局的概念說明 25 3.1.2 模型假設 29 3.1.3 均衡求解 37 3.2 模型應用說明 47 3.2.1 實證資料的轉換 47 第4章 情境模擬 49 4.1 法令規定變動 50 4.2 產業經濟變動 55 4.3 篩選賽局 57 4.3.1 現行評鑑制度的困難 57 4.3.2 評鑑制度篩選賽局的概念說明 58 4.3.3 模型假設 60 4.3.4 均衡求解 60 第5章 結論與建議 64 5.1 研究成果 64 5.2 後續研究方向 66 5.3 結語 67 參考文獻 68 附錄A 營造業評鑑分級基準表 70 附錄B 情境模擬計算表 7