Capital Structure Modigliani and Miller argued that capital structure is irrelevant, all other things being equal, but in the real world those other things are never equal. The factors that are ruled out of MM are neutral taxes, no capital market frictions, symmetric access to credit markets, and that firm finance policy reveals no information. Normally, arguments against the irrelevance of capital structure are based on these factors that MM assumed away (Villamil, n.d.). In the U.S., taxes on dividends are very different from the taxes paid on loan interest. There are transaction and bankruptcy costs; firms cannot borrow and lend at the same rate, and financial policy does reveal information. As such, MM does not hold in the real world, and this implies that capital structure does matter.

That capital structure does matter implies that for every firm there is an optimal capital structure. What that structure might be, however, is dependent on a wide range of factors, many firm-specific and some highly subjective. This results in firms having a wide range of capital structures, even within the same industry, and that might give the impression to the casual observer than capital structure does not matter. Yet, there are in all likelihood some very good reasons for the differences between capital structures of different firms.

The objectives of the firm and the personal taste of management -- especially its risk aversion -- are key elements that contribute to the choice of capital structure. In general, debt has a lower cost than equity, but it increases the risk to the company because it represents an obligation that must be paid from the firm's cash flows before it accrues to the shareholders. In contrast, equity is less risky but is more costly. All firms must make a tradeoff between the two, and firms that have many similarities will choose divergent courses. Consider the examples of Mattel and Clorox. Both firms deal in consumer products and they have relatively...

Yet, Mattel maintains a capital structure that is weighted to just over 50% debt. Clorox is financed almost entirely by debt. There are a few explanations for this disparity. Clorox pays lower taxes as a result of its policy, and it has a lower cost of capital. In addition, the company's ROE is high (actually, in three of the past five years it had negative equity). Mattel's strategy is more costly, but less risky. It pays more in taxes, and has a higher cost of capital, but does not face situations where it struggles to make debt payments or has negative equity book value.
Bradley, Jarrell and Kim (1984) argued that the question of optimal capital structure comes down to "an empirical issue as to whether or not the various leverage-related costs are economically significant enough to influence the costs of borrowing." This argument states that if the firm's degree of leverage is so high that its credit quality has declined (thereby increasing the cost of debt), then the optimal capital structure lies in a more balanced approach. The implication of this is that perhaps Clorox does not see its cost of borrowing increase despite its very high degree of leverage, or does not see it increase to the point where it eclipses the cost of equity. In addition, it also says that Clorox management has a high degree of risk tolerance as any deviation from the company's revenue or income stability would create a liquidity crisis. For Mattel, higher leverage would increase its borrowing costs. Additionally, Mattel's cash flow is very seasonal, whereas Clorox's cash flow is spread throughout the year, and that alone could account for the difference in risk tolerance between the executives of these firms.

Another wrinkle in the discussion is the issue of dividends. Apple, for example, just declared its first dividend since 1995 (Goldman, 2012). Even without the dividend, the company's stock price cruised well north of $550,…