1.0 Introduction
One of the most contentious financial issues that have provoked intense academic research during the last decades is the theory of capital structure. Capital structure can be defined as a 'Mix of different securities issued by a firm' (Brealey and Myers, 2003). Simply speaking, capital structure mainly contains two elements, debt and equity. In 1958, through combining tax and debt factors in a simple model to price the value of a company, Modigliani and Miller firstly begin to explore a modern capital structure theory, and their work inspired this area study.
However, the MM theory has no practical use because it lacks of direct guidance for companies to determine capital structure in real life (Baxter, 1967; Sarig and Warga, 1989; Vernimmen et al, 2005). During the past years, researchers strived to establish a more reasonable capital structure theory that can be put into practices efficiently, and they attempted to expand debt ratio and tax advantage factors into a new area. Myers (1984) states that only practical capital structure theories, which introducing adjustment cost that includes agency cost and information asymmetry problems, could provide a useful guidance for firms to determine their capital structure. However, from recent studies, Myers (2001) believes that how information differences and agency costs influence the capital structure is still an open question.
From this perspective, it is very important to review the development of these two factors which make theoretical research having a strong relationship with reality. Thus, this project will summarize the capital structure theories orientated by agency cost and asymmetric information from extant literature. Also some gaps and conflicts among theories of capital structure will be found and discussed in order to further improve this area study.
The rest of this project is arranged as follows. Section 2 will present the theories based on