Lando, David, Mamdouh Medhat, Mads Stenbo Nielsen, Søren Feodor Nielsen, "Additive Intensity Regression Models in Corporate Default Analysis", Forthcoming: Journal of Financial Econometrics, (2013).
Abstract: We consider additive intensity (Aalen) models as an alternative to the multiplicative intensity (Cox) models for analyzing the default risk of a sample of rated, nonfinancial U.S. firms. The setting allows for estimating and testing the significance of time-varying effects. We use a variety of model checking techniques to identify misspecifications. In our final model, we find evidence of time-variation in the effects of distance-to-default and short-to-long term debt. Also we identify interactions between distance-to-default and other covariates, and the quick ratio covariate is significant. None of our macroeconomic covariates are significant.
Keywords: default risk modeling, Aalen's additive regression model, martingale residual processes.