A standardized two-sex stable population

The “problem of the sexes” has been one of trying to reconcile inconsistent male and female demographic rates. The present paper deals with that question in the context of a two-sex stable population. A “rectangular” population, with equal numbers of persons in each age-sex group, is introduced as a standard, and a standardization relationship expressed in Eq. (3) relates changes in rectangular population rates to changes in age-sex composition. The standardization relationship is shown to satisfy a number of desirable properties and produce a realistic two-sex model. The standardization approach is then applied to data from Sweden 1973 and the United States 1963, and the results and their implications are discussed. In particular, it is seen that the intrinsic growth rate in a two-sex stable population is not necessarily bounded by the growth rate of the associated male and female one-sex stable populations.