Abstract: | We propose a structural model with an optimal switching of diffusion regimes that integrates a wide range of investment reversibility. The default boundary and switching thresholds are endogenously determined, and they enable us to comprehend the interrelated problems of the investment decision, capital structure, and credit risks. We examine not only the under/overinvestment but also the under/overdisinvestment. The leverage ratio decreases when the firm has an option to invest in a reversible project, which can alleviate the capital structure puzzle. Furthermore, the model significantly reduces the wide dispersion of yield spreads depending on the credit grade of bonds. |