有別於過去資本結構研究多採用長期或特定期間進行資本結構之研究,本研究利用部分調整模型並配合滾動視窗法,針對美國上市企業探討其長、短期的資本結構調整速度之差異,並觀察槓桿變動傾向及產業差異下資本結構的變化趨勢。實證結果顯示,長期而言不同產業之企業皆符合目標資本結構之推論,會以34%(約1.65年)之調整速度朝向目標資本結構調整。在短期的表現上,企業可能會受到外部環境的系統性衝擊,而選擇暫時性放棄目標資本結構之調整。此外,企業槓桿變動為負之年度相較於槓桿變動為正之企業年度,以及營運資金需求較小的產業,其調整至目標資本結構的速度會相對較快,說明在隨著時間推進下,環境變動與產業的異質性皆會影響企業資本結構之調整情形,且實質影響公司對於融資決策的選擇行為。本研究主要貢獻,在於藉由滾動窗期分段式分析調整速度之變化,除能透過短期變化反映經濟事件對於資本結構之影響外,亦能提供過去研究在不同觀察時間區段上,對於企業存有不同融資決策行為之解釋。
This study utilizes the partial adjustment models with a rolling windows regression approach to measure the effects of leverage on long-term and short-term speed of adjustments (SOA) of the publicly listed companies in the US for the period from 1996 to 2015. By estimating different periods of sample sets, our major findings are as follows. First, firms exist and pursue target capital structures in the long run and their SOA is approximately 34% (half-life 1.65 years). However, in some cases of short-term presentation, firms did not show obvious target capital structure temporarily. The presentation probably due to the systemic impact of the global economy. Second, the SOA of firms with increasing debts ratio is slower than the firms with decreasing. Furthermore, we indeed find that the SOA of firms varies with different industries indeed and the macroeconomic environment would cause distinct influence on industries. Finally, we argue that the rolling window regression approach can provide an extended explanation of financing strategies and behavior of firms under separated periods to compare with a single long-term viewpoint.