Statistical Analysis in surveys is often facing missing data. As case-wise deletion and single imputation prove to have undesired properties, multiple imputation remains as a measure to handle this problem. In a longitudinal study, where for some missing values past or future data points might...

We model credit rating histories as continuous-time discrete-state Markov processes. Infrequent monitoring of the debtors' solvency will result in erroneous observations of the rating transition times, and consequently in biased parameter estimates. We develop a score test against such...