Tesi doctoral- Universitat Autònoma de Barcelona. Departament de Geografia ; Centre d'Estudis Demogràfics, 2013

One of the foremost problems in formal demography has been including information on the vital rates from both males and females in models of population renewal and growth, the so-called two-sex problem. The two-sex problem can be conceived as a subset of the analytical problems entailed by multigroup population modeling. This dissertation characterizes the two-sex problem by means of decomposing the vital rate components to the sex-gap between the male and female single-sex stable growth rates. A suite of two-sex models for age-structured models from the literature are presented in a standard reproducible format. A new variety of age-structure, age based on remaining years of life, is presented. Analogous models of population growth for the singlesex and two-sex cases are developed for populations structured by remaining years of life. It is found that populations structured by remaining years of life produce less sex-divergence than age-structured models, thereby reducing some of the trade-offs inherent in two-sex modeling decisions. In general, populations structured by remaining years are found to be more stable over time and closer to their ultimate model stable structures than age-structured populations. Models of population growth based on remaining-years structure are found to diverge from like-designed age-structured models. This divergence is characterized in terms of the two-sex problem and we call it to two-age problem.