產權、成長機會與債務槓桿—基於中國企業與非線性關係的實證

Abstract

大部分實證文獻指出，企業的成長機會（以Tobin’s Q代理）與債務槓桿大多數情況呈線性負相關，少數文獻主張是正相關，但過去的成長機會理論並無法解釋此文獻分歧。為了解決分歧，本文直接以Tobin’s Q（以下簡稱Q）的理論性質切入，加入Q的平方項，並認為Q與債務槓桿呈現U字型曲線關係。Q對債務槓桿的影響分為負向影響與正向影響，在曲線前半部，淨影響效應為負；在曲線後半部，淨影響效應為正。負向影響為隨著Q越高，公司的權益融資成本越低，越傾向權益融資，進而降低債務槓桿；正向影響為隨著Q越高，投資人的權益投資成本越高，參與增資的傾向越低，公司只得以債權融資彌補資金缺口。本文使用2008至2017年的中國上市企業平衡樣本，證明U型曲線關係存在，並主張因為民營企業的Q較國營企業的Q高，故其曲線較為顯著。本文的投資管理意涵為，即使高Q的公司亟欲增資，但投資人可能因Q過高而不買單。

Most empirical literature report a negative relationship between a firm’s growth opportunities (proxied by Tobin’s Q) and debt leverage, yet a few argue a positive relationship. To author’s knowledge, however, past theories fail to solve this conflict. This study provides a fresh viewpoint by investigating the concept of Tobin’s Q (abbreviated as Q) and its quadratic function, and proposes a U-shaped relationship between Q and leverage. This study argues that there coexist a negative and positive influence of Q towards leverage, the former prevails in the first part of the U-shaped relationship, the latter in the second. Specifically, a firm tends to choose equity financing as Q increases due to lower cost of equity financing; an investor tends to pull back from seasoned equity offerings as Q increases due to higher cost of equity investing. This rationale is supported by a panel analysis of Chinese listed firms from 2008 to 2017. Furthermore, this U-shaped relationship is more significant among private enterprises than state-owned enterprises, since the former have higher Q. This study implies that even though firm wish to pursue seasoned equity offering, their investors might not always cater to them when Q is too high.