On Fisher’s reproductive value and Lotka’s stable population

Carlos Galindo, Consejo Nacional de Población

The main purpose of this paper is to finally debunk the idea that Fisher implied the reproductive value (RV) of the first age group must be equated to 1 (other valuations answer different research questions). Fisher (1927) and other researchers stated that dissimilar generation times must be considered when comparing subpopulations (confront with Keyfitz and Caswell 2005). Fisher’s (1927) original paper also points out, in a most unusual way, the links with Lotka’s stable theory. RV has never been presented along with proper interpretation of stable concepts used in its development (see Fisher 1927, 1930); revisiting Lotka’s thermodynamic assumptions will prove helpful to avoid confusions and misinterpretations of RV and related concepts as stable equivalent value and population momentum.