The Effect of Forward Markets on the Debt-Equity Mix of Investor Portfolios and the Optimal Capital Structure of Firms
证明，如果存在模拟股票远期合约的证券（如期权），投资者和企业可以规避市场不完美，从而改变投资组合的债务-股权混合，并允许企业提高债务水平而不增加破产风险。
This paper demonstrates that the various market imperfections that have been suggested to explain observed portfolio choices and capital structures can be circumvented if securities (e.g., options) can be traded that simulate forward contracts on stock. It is shown that if the risk-adjusted returns to bondholders exceed the returns to stockholders (to reflect personal tax differences) tax-exempt investors will prefer a combination of these synthetic forward purchases and corporate bonds to purchasing stock directly. They will not, as has been suggested, include stock in their portfolios for diversification purposes when they can alternatively purchase securities that simulate forward contracts. It is also shown that firms that can sell synthetic forward positions on their own stock can essentially guarantee that sufficient funds will be available to meet their bond obligations. This gives firms the opportunity to increase their debt levels without increasing the possibility of bankruptcy and the corresponding administrative and agency costs.