Discrete time models are used in Ecology for describing the evolution of an agestructured population. Usually, they are considered from a deterministic viewpoint but, in practice, this is not very realistic. The statistical model we propose in this article is a reasonable model for the case in...

The hazard of mortality is usually presented as a function of age, but can be defined as a function of the fraction of survivors. This definition enables us to derive new relationships for life expectancy. Specifically, in a life-table population with a positive age-specific force of mortality...

An age-structured model for childhood obesity at population level is fitted to empirical data in order to predict the proportion of overweighted and obese children in the 6-8 and 9-12 year old classes in the region of Valencia, Spain.

A model of the governmental control of age at retirement uses population age structures, productivity, employment, and money income. The sustainability criterion is a sufficient level of individual money income for all ages. The decision variables are the variable age at retirement and the...

Ergodicity for a nonlinear age-dependent population model with diffusion and T-periodic vital rates is investigated. The existence of at most one non trivial T-periodic and nonnegative separable solution is proved.