Optimal Debt and Profitability in the Trade‐Off Theory
构建了一个动态杠杆模型，考虑利息税盾和内生违约成本，发现当借贷约束不紧时，最优债务平衡边际税盾与边际违约成本；与常规解读相反，盈利增加反而降低最优杠杆率。
ABSTRACT I develop a dynamic model of leverage with tax deductible interest and an endogenous cost of default. The interest rate includes a premium to compensate lenders for expected losses in default. A borrowing constraint is generated by lenders' unwillingness to lend an amount that would trigger immediate default. When the borrowing constraint is not binding, the trade‐off theory of debt holds: optimal debt equates the marginal interest tax shield and the marginal expected cost of default. Contrary to conventional interpretation, but consistent with empirical findings, increases in current or future profitability reduce the optimal leverage ratio when the trade‐off theory holds.