Final answer:
The most important factors in deciding the mix of debt and equity in a firm's capital structure are business risk, cash flow, and external risk assessment. These factors help determine the firm's capacity for debt, its ability to service that debt, and how the external market views the firm's financial health.
Step-by-step explanation:
When deciding the appropriate mix of debt and equity in a firm's capital structure, several factors must be considered. Among these, three stand out as particularly important: business risk, cash flow, and external risk assessment. Business risk refers to the stability of the company's revenues and the predictability of its sales, which can dictate the level of leverage a firm can safely undertake. Cash flow is crucial as it determines a firm's ability to service its debt and is a direct indicator of financial health. Finally, external risk assessment is vital because it influences a firm's ability to raise funds at favorable rates and impacts the perceptions of lenders and bond raters, which can affect the cost of capital.
Understanding the trade-offs between the control provided by debt financing and the shared ownership when issuing stock is fundamental to capital structure decisions. Debt financing, while obligating the firm to interest payments, retains the control within the existing management, not subjecting operations to shareholder decisions. Conversely, issuing stock dilutes ownership and subjects the firm to the demands of shareholders and a board of directors but does not add to financial obligations like scheduled interest payments in stressed financial periods.