Parity-Dependent Fertility in a Population with Natural Fertility in Northern Sweden 1720-1900

Abstract

Recent discussion has questioned the usefulness of the concept of natural fertility and Swedish data have shown very poor fit to proposed models for natural fertility. Skellefteå is an example of a parish with a natural fertility regime, in which prenuptial births and conceptions cause deviation from the Goale-Trussel model. Dynamic analysis of the risk of passing from one parity to another shows that there is a systematically changing pattern over time, suggesting a change of nonparity dependent control, in a period with no sign of parity-dependent family limitation methods. It is also well known that birth intervals tend to increase with maternal age and higher parity. However, these two concepts—age ofmother and parity—are highly correlated. When there is no evidence of parity-dependent limiting methods, parity dependence can be explained by coital frequency and maternal age.