Modelling mortality at oldest ages using vitality model: The case of French cohorts

Te objective in this paper is to investigate the performance of the new vitality-based approach that canaccount for variability around the deterministic natural decay trend of vitality in modeling mortality atoldest ages. First, we compare the estimated values of the natural vitality decay parameters that areassumed to follow the Gompertz law (i.e., b and c) to that from a Gompertz law fitted in conventionalway to the observed data. Second, we compare the estimated survival probabilities from this new modelto that estimated from the optimal parametric model proven for these age ranges (i.e., the Beard model).