Structural models of credit risk provide poor predictions of bond prices. We show that,
despite this, they provide quite accurate predictions of the sensitivity of corporate bond
returns to changes in the value of equity (hedge ratios). This is important since it
suggests that the poor performance of structural models may have more to do with the
influence of non-credit factors rather than their failure to capture the credit exposure of
corporate debt. The main result of this paper is that even the simplest of the structural
models [Merton, R., 1974. On the pricing of corporate debt: the risk structure of interest
rates. Journal of Finance 29, 449–470] produces hedge ratios that are not rejected in
time-series tests. However, we find that the Merton model (with or without stochastic
interest rates) does not capture the interest rate sensitivity of corporate debt, which is
substantially lower than would be expected from conventional duration measures. The
paper also shows that corporate bond prices are related to a number of market-wide
factors such as the Fama-French SMB (small minus big) factor in a way that is not
predicted by structural models.