Intergenerational continuities in childbearing in developed countries

Michael Murphy, London School of Economics and Political Science (LSE)

The relationship between fertility of parents and children has been designated as ‘weak’ by many investigators who have looked at this topic. This paper reviews the evidence over the past century and argues that, even allowing for problems with available data sources, the relationship was generally close to zero but slightly positive for pre-transitional populations, but that it has tended to become more substantial over time in developed countries and it is now of a similar order of magnitude as widely used explanatory variables such as female educational level. Questions about intergenerational fertility have recently been included in large-scale surveys in developed countries including the Fertility and Family Surveys (FFS), International Social Survey Programme (ISSP) 2001 round, the Generations and Gender Programme (GGP) and one large UK national source (UNSOC). These databases considerably extend the number and types of countries for which such information is available. Two main research questions are addressed. The first is to establish how far the increase in the strength of the relationship has continued and how far similar patterns hold for other areas of the World with similar levels of development. The second research question is how far the simple correlations between fertility of parents and children can be explained by differences between population subgroups such as by educational level or religion. The first question is addressed by presenting correlations of fertility of successive generations. The second question is addressed by presenting generalised linear models to assess the relative strength of inherited fertility, educational level and religious attendance across a wide range of countries.