Optimal capital structure

Optimal capital structure
Primary topic
Related topics
Methods and techniques

Optimal capital structure is a balanced set of dept and stock that helps to maximize company value (or stock price). The benefit of debt is lowest cost of capital, but accompanied with higher financial risk to shareholders. Therefore, company should find an equilibrium when benefit of debt is similar to marginal cost.

Measuring capital structure[edit]

The most popular measure that helps to optimize capital structure is WACC (weighted average cost of capital). It is a calculation of a firm's overall cost of capital in which each category of capital is proportionately weighted. All capital sources - stocks, bonds and any other long-term debt - are included in a WACC calculation.

\(\text{WACC} = \left ({E \over {V}}\right) \cdot r_E + \left ({D \over {V}} \right) \cdot r_D \left (1-T_c\right)\)


  • \(\ D \) is the value of debt,
  • \(\ E \) is the value of equity,
  • \(\ V \) is the market value of the company,
  • \(\ T_C \) is the tax rate,
  • \(\ r_D \) is the cost of debt,
  • \(\ r_E \) is the cost of equity.

Capital structure choice determinants[edit]

Variation of debt ratios theories suggest that companies select their capital structure according to their activity. Costs and profits are determinated on attributes of the analyezed company and they are in connection with equity financing and debt. According to this, there are some different theories of the capital organization. Any of them can cause company’s choice in it’s debt-equity forasmuch each theory brings up attributes that can affect this choice. The attributes are discribed below (S. Titman 1988, p.1-6):

  • The value of asset collateral – becouse majority of capital structure theories contend that the kind of asset can influence choice of capital structure. One of theories suggests that companies can boost their equity’s value by dispose secured debt, by dispossession of assets from their present unsecured creditors. Some of theories demonstrate that there can appear costs connected with issue of securities. Company’s managers have better knowledge about those securities and their costs than external shareholders. Those costs may be avoided by selling debts that are secured by wealth with specified value. Because of that, firms that are in possession of wealth that may be used as collateral are more likely to increase their debt issue as long as they have possibility to do this.
  • Non-debt tax shields – tax breaks connected with depreciation and those involved in investments are substitues for debt financing tax benefits. Companies that can boast wide non-debt tax shields on their chash flow indicate capital structures with lower debt.
  • Growth – equity-controlled companies are more likely to invest in expropriate assets from bondholders. Costs that are connected with this kind of relationship are very possible in companies that are classfied as growing ones. These firms are more flexible in their future investments choices. Predicted growth can discourage investors because of its long-term debt. However, ratio which discribe short-term debt may be connected with positive image of growing firms. But the most important thing to do for the company is to replace long-term financing with short-term.
  • Individuality – Debt ratios are connected in the negative with unique specification of products and services. Clients, employees and suppliers that are cooperate with company that manufacture unique products are possibly at risk of high costs in case of manufacturer liquidation. Probably, suppliers and workers have got specific skills and experience, and clients do not have any substitute for product and this caused negative view of individuality.
  • Industry classification – manufacturers producing products that require specialized service and spare parts are connected with high cost of liquidation. Because of this, companies producing machines and gear need to be financed with possibly the lowest debt.
  • SizeCompany size is attribute that levarage ratios can be connected to. Large companies have got tendency to be diversified, and because of that they have lower predisposition to bankruptcy. Issuing debt and equity securities cost is related to size of the company. Relative small companies pay more to issue equity then big firms. According to that fact, small firms are more likely to be leveraged in high level then big ones, and because of lower fixed costs may prefer to use short-term loan.
  • Profitability – retained earnings are preferred way of encreasing capital. Secondly, there is raising capital from debt, and finally from issuing new equity. Issuing new equity costs can be the main reason of this behavior (costs that arise in connection to asymmetric information and costs connected with transactions). Past profitablity and coming from it value of earnings that have ability to retained, should be significant determinant of capital structure.

There are various of analyzes that was aiming at capital structure and was based on levarage in companies. Refering with some agency models connected with capital structure, there are many works that have noted accociation between comapny's value and levarage. Researches into reaction of stock price on security issuance and redemption announcements find that levarage-increasing ones are connected with positive reaction on stock price and levarage-decrasing with negative. Stock repurchases and debt-for-equity exhachanges are examples of levarage-increasing annnouncements and isuuing equity is example of levarage-dicrasing announcement (P. Berger 1997, p.2).


Author: Maciej Soczówka