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Demographers often study datasets that are riddled with missing records and partial information. To overcome such limitations, Colchero, when he was at MPIDR, developed the general approach of “Bayesian Survival Trajectory Analysis” and made it publicly available through the now popular R package BaSTA (Colchero and Clark 2012, Colchero et al 2012). This framework has been applied, for example, to estimate age-specific mortality from 16th Century marriage records (Villavicencio et al. 2015) and to test hypotheses on the existence of negative senescence in indeterminate growers by treating age and size as latent states (Colchero & Schaible 2014). In a recent research article published in the journal PNAS, we extended the BaSTA framework a Bayesian hierarchical model that builds on the multi-event framework was applied to estimate age and to estimate age-specific mortality and dispersal for populations in which one or both sexes disperse from the study area.