Are deliberate birth spacing effects in fact statistical and bio-demographic artefacts? A critical study with data from the Netherlands

Jan Van Bavel, Leuven University
Jan Kok, International Institute of Social History

Our paper will take a critical stance towards the recently revived thesis that fertility might have been controlled before the fertility transition in Europe. To this end, we will use as guidelines critiques from both a methodological-statistical as well as a bio-demographic point of view. First, we review the kind of regression models that have been used in order to detect non-parity specific fertility control with individual level data. Particular attention will go to unobserved sources of heterogeneity and possible statistical solutions. Secondly, we discuss how birth spacing may be influenced by malnutrition and what the consequences for our statistical models may be. We apply our models to individual-level data about pre-transition populations in the western-central part of the Netherlands, including both rural municipalities and two major cities. The fertility histories for first-married women we use are uncensored in that we have followed them, as they migrate, through different localities.