Koopman, S., Lucas, A. and Monteiro, A. (2008). The Multi-state Latent Factor Intensity Model for Credit Rating Transitions Journal of Econometrics, 142:399--424.
Koopman, S. and Lucas, A. (2008). A Non-Gaussian Panel Time series Model for Estimating and Decomposing Default Risk Journal of Business and Economic Statistics, 26(4):510--525.
