Optimal Trading and Tax Option Value of Defaultable Bonds with Asymmetric Capital Gain Taxes

Current US tax laws provide investors an incentive to time the sales of their bonds to minimize tax liability. This gives rise to a tax-timing option that affects bond value. In reality, corporate bond investors’ tax-timing strategy is complicated by risk of default. Existing term structure models have ignored the effect of the tax-timing option, and how much corporate bond value is due to the tax-timing option is unknown. In this chapter, we assess the effects of taxes and stochastic interest rates on the timing option value and equilibrium price of corporate bonds by considering discount and premium amortization, multiple trading dates, transaction costs, and changes in the level and volatility of interest rates. We find that the value of the tax-timing option accounts for a substantial proportion of corporate bond price even when interest rate volatility is low. Ignoring the timing option value results in overestimation of credit spread, and underestimation of default probability and the marginal investor’s income tax rate. These estimation biases generally increase with bond maturity and credit risk.