信用評等與資本結構關聯性之研究-以台灣公司為研究對象

Abstract

傳統關於資本結構理論已經有相當豐富的研究成果，從最早期的營業淨利法(NOI Approach)、淨利法(NI Approach)到著名的M&M資本結構無關論，後來引起學術界的爭相討論，後發現資本結構並不是無關的，產生了考慮舉債成本與利益的抵換理論(最適資本結構理論)，使得企業是否存在最適資本結構成為財務管理領域裡備受爭議的焦點，到後期將權益發行成本考慮進去的融資順位理論等。 直到2006年由Darren在Credit Rating and Capital Structure裡提出的信用評等會直接影響到資本結構之後，信用評等的重要性日益顯現。因此，本文目的即為探討信用評等與資本結構的關係。 本文利用的是來自台灣經濟新報上市上櫃公司的財務資料，信用評等則來自中華信評，並利用敘述性統計以及多元迴歸分析分別對三個模型做檢測，又將資料分成兩種型態分別研究。經過研究後獲得如下結論：信用評等對於資本結構確實會有影響，特別是在信用評等位於容易變化的公司，的確會有比信評居於穩定狀態的公司舉債較少的情況出現。

There have been many famous theories about capital structure. From the NOI Approach and NI Approach to the most popular one M&M’s Capital Structure Irrelevance Theory, which have caused lots of disputes in the field of financial management. Then, some proposed the Trade Off Theory, which indicates both cost and benefit should be considered while managers make decisions. This theory differed from M&M’s theory, which also brought about many arguments. Afterwards, the theory about the cost of issuing equity showed up. The impact of credit rating on capital structure hasn’t been valued much until Darren’s Credit Rating and Capital Structure (2006). Darren outlined that credit rating directly affected capital structure decisions. We use companies in Taiwan to test whether credit rating affects directly capital structure. Also, this paper tried to test whether firms near a credit rating upgrade or downgrade issue less debt relative to equity than firms not near a change in rating. This paper uses multiple regression to test three models, and divides data into two patterns. We concluded that: Credit rating directly affects capital structure decisions and we also find out the possibility that firms near a credit rating upgrade or downgrade issue less debt relative to equity than firms not near a change in rating.