新巴賽爾資本協定之制訂與實施，將使信用評等對企業融資決策之影響程度提升。過去的文獻中，鮮少討論信用評等改變對企業資本結構之影響，因此本文以1997年至2008年台灣上市、上櫃公司，但不含金融、證券、投資、媒體等產業為研究對象，並依企業是否有發行公司債，將樣本分為公開舉債樣本及銀行借款樣本，並參考Kisgen(2006)及Kisgen(2007)，分別探討(1)信用評等改變對企業資本結構決策之影響，(2)信用評等改變對資本結構理論之影響。 實證結果顯示，前一年度信用評等調升之企業，會增加負債之舉借，又以公開舉債樣本增加幅度較大，顯示當企業可以透過發行公司債來募集資金時，通常會傾向大額發行，以降低其發行單位成本。而前一年度信用評等調降之企業，會減少負債之舉借，以銀行借款樣本較為顯著，表示當企業信用評等被調降時，由於銀行對信用評等改變的敏感度較債權人高，會有緊縮銀根行為之產生。 信用評等改變對資本結構理論影響之實證結果為，符合靜態抵換理論，但不符合融資順位理論，僅銀行借款樣本中之信用評等調升變數顯著為正，顯示信用評等調升之企業會增加長期負債之舉借。 Response to New Basel Capital Accord, credit ratings becomes an important factor to influence corporate financing policy. Refers to Kisgen (2006) and Kisgen (2007),we use a sample of listed companies in Taiwan over the period of 1997 to 2008 to investigate：(1) how changes in credit ratings affect a firm’s subsequent capital structure decisions. (2) whether firms incur a credit ratings upgrade or downgrade would influence long-term debts and thus depart from the Pecking order theory and the Static trade-off theory. The findings reveal that credit ratings is an important factor to determination of capital structure. The results show that firms incur credit ratings upgrade would issue more net debt relative to net equity and downgrade would issue less net debt relative to net equity. In addition, our results support the Static trade-off theory but not support the Pecking order theory, after taking credit ratings into consideration.
