We present an implementation of split-population duration regression in the spduration
(Beger et al., 2017) package for R that allows for time-varying covariates. The statistical model accounts
for units that are immune to a certain outcome and are not part of the duration process the researcher
is primarily interested in. We provide insights for when immune units exist, that can significantly
increase the predictive performance compared to standard duration models. The package includes
estimation and several post-estimation methods for split-populationWeibull and log-logistic models.
We provide an empirical application to data on military coups
