Several financial models explain how companies approach capital structure decisions. Each theory provides a different understanding of how debt and equity affect risk, financial performance, and firm value.
Modigliani–Miller Theory
The Modigliani–Miller Theory states that under perfect market conditions, a company’s value is unaffected by its capital structure. When corporate taxes are considered, the model highlights the advantage of using debt, as interest payments reduce taxable income. This theory emphasises the benefit of tax shields in shaping optimal leverage.
Trade-off Theory
Trade-off theory is a financial model that suggests a firm chooses its capital structure by balancing the benefits of debt financing against its costs. The main benefit is the tax shield from interest payments, while the main costs are the risks of financial distress, such as bankruptcy and agency costs.
Pecking Order Theory
The Pecking Order Theory suggests that companies prefer funding options in the following order:
Internal funds
Debt
Equity
This preference is based on lowering financing costs and avoiding signals that may imply stock overvaluation. The theory focuses on real-world behaviour rather than maintaining a strict target capital mix.
Agency Cost Theory
The Agency Cost Theory highlights how conflicts between managers, shareholders, and lenders affect financial decisions. Debt can improve managerial discipline by imposing repayment obligations. However, excessive debt may create constraints and limit operational freedom. The theory identifies how balancing control and flexibility is important for long-term stability.