This dissertation studies capital structure decisions of levered and unlevered firms using the modeling framework of Leland (1994). The first chapter, Cash Holdings and Financial Constraints, focuses on optimal management of cash holdings by equity holders of a levered, financially constrained firm. I add financial constraints as a market friction to the traditional model. A financially constrained firm is not able to issue new equity to subsidize net operating losses and is subject to premature, costly default on its straight debt. The more constrained the firm is the less equity it is able to issue and the more likely it is to default. Equity holders mitigate the effects of financial constraints by managing a costly cash account, based on retained net operating profits. In the theoretical section, I show that firms that are more financially constrained optimally hold more cash but remain more likely to default compared to their less constrained counterparts. Hence, firms with higher cash holdings are riskier, and claims on their assets should trade at a premium. In the empirical section, I find evidence of this observation in straight debt and common equity markets. Firms with higher cash holdings are observed with higher yields on debt and higher returns on equity,
In the second chapter, Contingent Capital Bonds (CCBs) and Capital Structure Decisions, a joint work with Dwight Jaffee and Alexei Tchistyi, we provide a formal model of CCBs, a new instrument offering potential value as a component of corporate capital structures for all types of firms, as well as being considered for the reform of prudential bank regulation following the financial crisis of 2007-2008. CCBs are debt instruments that automatically convert to equity if and when the issuing firm reaches a specified level of financial distress. We develop closed form solutions for CCB value under three assumptions. First, the firm is allowed a tax deduction on its CCB interest payments as long as the security remains outstanding as a bond. Second, we assume that adding CCBs to a firm's capital structure has no impact on the level of the firm's asset holdings. Third, we require that the CCB conversion to equity occurs at a time prior to any possible default by the firm on its straight debt. The key contribution of our work is that we provide a formal financial model in which the effects of alternative CCB contract provisions can be analytically evaluated. We show that a firm will always gain from including CCB in its capital structure as a result of the tax shield benefit. A firm creating a de novo capital structure, assuming it faces the regulatory constraint that the CCB can only replace a part of what would have been the optimal amount of straight debt, will always issue at least a small amount of CCB. The reduction in expected bankruptcy costs ensures a net gain, even if the tax shield benefits are reduced. We show that a firm will never add CCB to an existing capital structure, assuming that it faces the regulatory constraint that the CCB can only be introduced as part of a swap for a part of the outstanding straight debt. While the swap may increase the firm's value - the value of reduced bankruptcy costs may exceed any loss of tax shield benefits - the gain accrues only to the holders of the existing straight debt. As in a classic debt overhang problem, equity holders will not act to enhance the overall firm value. We show that for a Too-Big-To-Fail firm, for which the straight debt is risk free because the bond holders correctly assume they will protected from any potential insolvency, under a regulatory limitation on the amount of debt such a firm may issue, a CCB for straight debt swap reduces the value of the government subsidy by reducing the expected cost of bondholder bailouts. While this has a taxpayer benefit, the equity holders of such a firm would not voluntarily participate in such a swap. We demonstrate that CCBs create an incentive for market manipulation. CCB holders may have an incentive to manipulate the stock price to a lower value if the amount of equity they receive at conversion is sufficiently high. Equity holders may have an incentive to manipulate the stock price down if the amount of equity they give up at conversion is sufficiently low. We summarize, that the regulatory benefits of CCB issuance with respect to bank safety will generally depend on the CCB contract and issuance terms. Perhaps most importantly, the regulatory benefits vanish if banks simply substitute CCBs for capital, leaving the amount of straight debt
unchanged. It is thus essential to require CCB issuance to substitute for straight debt (and not for equity).