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 Ilfe (Baxter, 1967; Sarlg 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, ould 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 heories 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 agency costs that causes the conflicts between equity holders and debt holders or managers. Section 3 will Illustrate from two areas, Interplay of capital structure and Investment, followed by signal effect of debt ratio, to show the theories based on asymmetric information. In conclusion, Section 4 will summarize the entire essay and suggest further research direction of capital structure theory. 0 Capital structure theories based on agency costs Although Berry and Means (1931, cited in Myers, 2001) state an adverse relationship between the separated ownership and corporate control status, it commonly admits that Jensen and Meckling (1976) firstly conducted the research in how agency costs determine capital structure (Harris and Ravlv, 1991 Over the past decades, researchers have tried to add agency costs to capital structure models (Harris and Raviv, 1991). The perfect alignment between firm investors and firm agencies, such as managers, does not exist (Myers, 2001 ).
According to Jensen and Meckling (1976), company agents, the managers, always emphasize on their own interests, such as high salary and reputation. Also these company agents use 'entrenching investments', which make the asset and capital structure orientated by the 1 OF3 company holders (Chen and Kensinger, 1992). However, Myers (2001) believes that the firm holders can reduce such transferred value through using different kinds of methods of control and supervising, but he further points out the weakness that these methods are expensive and reduce returns.
As a result, the perfect monitoring system is out of work, and agency costs are produced from these conflicts. According to Jensen and Meckling (1976), the conflicts between investors and agencies are generally divided into two types. The first conflict occurs between debt holders and equity holders, and the second conflict is from between equity holders and managers. Consequently, all the capital structure theories based on agency costs can be also classified based on these two conflicts. In the rest of this section, each individual conflict will be separately discussed. 1 Conflicts between Debt holders and Equity holders Jensen and Meckling (1976) point out that agency costs problems happen in determining the structure of a firms' capital when the conflict between debt holders and equity holders is caused by debt contracts. Similar to Jensen and Meckling's conclusion, Myers (1977) observes that since equity holders bear the whole cost of the investment and debt holders get the main part of the profits from the investment, equity holders may have no interest in investing in value-increasing businesses when ompanies are likely to face bankruptcy in the short term future.
Thus, if debt occupies a large part of firms' capital, it will lead to the rejection of investing in more value-increased business projects. However, in 1991, Harris and Raviv cast a contrasting opinion to adjust the capital structure theory based on this conflict. They point out that most debt contracts give equity holders a push power to invest sub- optimally investment project. If the investment fails, due to limited liability, debt holders bear the consequences of a decline of the debt value, but equity holders get ost of yields if the investment could generate returns above the debt par value.
In order to prevent debt holders from receiving unfair treatment, equity holders normally get less for the debt than original expectation from debt holders. Thus, the agency costs are created by equity holders who issue the debt rather than debt holders' reason (Harris and Raviv, 1991). Tradeoff capital structure theory has a basic and strong relationship with this type of agency costs. However, different researchers hold various explanations of the relationship.
Myers (1977) points out the debt cost eason, Green (1984) announces that convertible bonds can reduce the asset substitution problem which comes from the tradeoff theory, Stulz and Johnson (1985) consider about collateral effect. In the end, only Diamond model (1989) is widely accepted. If Equity holders do not consider reputational reason, they are willing to trade relatively safe projects, but this activity will lead to less debt financing (Diamond, 1989; Mike et al, 1997). Diamond model (1989) assumes two tradeoffs, risky and risk-free, to show that the debt repayment should consider both possible nvestment plans.
Furthermore, Mike et al (1997) use empirical evidence to indicate how to use debt to trade off these two optional investment plans. Moreover, in 1991, Harris and Raviv expanded Diamond's model to three investment choices. They point out that one choice of investment can only contain the risk-free project, one option In fact, since the reputation factor is vital for a manager, managers are willing to choose risk-free investment projects that have more possibility of success. Consequently, the amount of debt is often reduced by managers.