Intrinsically dynamic models (IDMs) depict populations whose cumulative growth rate over a number of intervals equals the product of the long term growth rates (that is the dominant roots or dominant eigenvalues) associated with each of those intervals. Here the focus is on the birth trajectory...

When fertility increases in a previously stable population, the new stable population will be younger than the old one, and the two age distributions will cross at the mean age of the populations.

Many studies have examined Keyfitz’s population momentum, a special case of inertia in long-term population size resulting from demographic transition to the stationary population growth rate. Yet, population inertia can be produced by any demographic perturbation (i.e., not just perturbations...

Formal demography has yet to move beyond assuming that demographic rates are constant over time, an assumption that is both unrealistic and constraining. To generalize the fixed rate stable model to the changing rate dynamic model, this paper explores the mathematical regularities that underlie...

The age-specific growth function of an observed population and the reproductive value function based on the population´s current vital rates determine the intrinsic rate of growth implied by those vital rates through the simple relationship given in equation (1). That equation establishes the...

Many studies have documented a negative association between macroeconomic indicators and fertility in times of economic crisis. These studies are based on research designs that do not allow for excluding that the observed association is driven by confounders. The aim of the present paper is to...

This paper presents an analysis of the differential growth rates of the farming and non-farming segments of a rural Scottish community during the 19th and early 20th centuries using the variable-r method allowing for net migration. Using this method, I find that the farming population of Orkney,...

This paper describes marriage and partnership patterns and trends in rural KwaZulu-Natal, South Africa from 2000-2006. The study is based on longitudinal, population-based data collected by the Africa Centre demographic surveillance system. We consider whether the high rates of non-marriage...

This study attempts to examine the extent to which women have control over their sexuality within marriage and its implication for the spread of HIV/AIDS. The survey was carried out in metropolitan Lagos. The study shows that women have some control over their sexuality especially during certain...