本研究以2004年第1季至2008年第3季之間，國內共449家上市公司為研究對象，採用縱橫資料迴歸模型（panel data regression model）及縱橫門檻迴歸模型（panel threshold regression model）來探討公司財務受到限制（financial constrained）時，其公司特性與總體經濟條件因素對於資本結構的影響是否會發生改變？與財務未受限（financial unconstrained）公司是否會產生差異？以及採用不同方式劃分樣本，其結果的異同又為何？ 實證結果顯示：不論以外生或內生決定劃分準則的方式區分樣本，財務受限與未受限公司在規模、獲利能力、未來的成長性等公司特性變數對負債比率的影響上，皆獲得完全相同的結果，亦即依序呈現顯著正相關、顯著負相關以及顯著負相關，此與過去相關文獻一致；而總體經濟條件因素對公司負債比率的影響，則只能符合過去文獻結果的部分，亦即不是財務受限公司的負債比率與總體經濟條件因素有呈現順循環（pro-cyclical）的現象，就是財務未受限公司的負債比率與總體經濟因素有呈現逆循環（counter-cyclical）的現象，但是卻未出現同時成立的結果。 This study is an analysis of 449 Taiwanese firms that are in operation between the first quarter of 2004, and the third quarter of 2008. A panel data regression model and a panel threshold regression model are used to analyze whether the impact of firm-specific and macroeconomic condition variables on the capital structure changes when one firm is financially constrained. The study also assesses whether the results of the financially firms differ from those of unconstrained firms. Also to be determined is whether using different methods of splitting the samples would render any difference. Our results show that no matter what method of splitting samples we use, the impact of the size, profitability, and future growth on the debt ratio of financially constrained and unconstrained firms are the same. The empirical results show that the relations between above mentioned firm-specific variables and the debt ratio are significantly positive, significantly negative, and significantly negative in turn, as to previous studies. Furthermore, the impact of macroeconomic conditions on the debt ratio of the firms is only consistent with part of the results of previous studies. This means that there are two findings. First, the debt ratio of firms in our financially constrained sample varies pro-cyclically with macroeconomic conditions. Additionally, the debt ratio of firms in our financially unconstrained sample varies counter-cyclically with macroeconomic conditions. However, the results are not found simultaneously.
