We use an exogenous, forward-looking measure of price uncertainty to examine the effect of uncertainty on the use of covenants in private and public debt contracts. The effect of uncertainty differs significantly in loans versus bonds, suggesting that private and public lenders face different incentives when contracting under high uncertainty. In loans, uncertainty increases the use of performance-based covenants. In contrast, covenant usage decreases in bonds, but firms with low agency conflicts mainly drive this effect. However, bondholders require higher spreads to offset the lack of protection with fewer covenants. Hedging does not affect the covenant-uncertainty relationship for debt contracts.

We develop a dynamic capital structure model in which interest rates are stochastic and driven by three state variables: level, slope, and curvature of the yield curve in an arbitrage-free Nelson-Siegel model. Our analysis suggests that the yield-curve factors are critical determinants of the capital structure of firms and that an increase in any of the three factors is followed by an increase of the firm’s leverage and a shortening of its debt maturity. We perform a two-stage least squares system of equations that accounts for the joint determination of leverage and debt maturity and confirms our model’s predictions.