Determination of a Feedback Vector that Generates a Non-decaying Oscillation in a Model Population

The parish registers of Penrith, Cumbria, have previously been used to provide the records of a model population of value to theoretical population biologists, particularly in the determination of oscillations and computer modelling. The registers contain information on named individuals, so permitting the extraction of further information of the population dynamics of the community. The derivation of a feedback vector by Ackermanʹs pole placement technique illustrates the expected age-specific gains/losses to the female breeding population (by immigration/emigration and by unmarried women) for any deviation from the steady-state population level to maintain the long-wavelength oscillations in births and deaths.