Analysts of the first demographic transition, which took place in western Europe between the late 19th century and mid-20th century, assumed that the gradual decline in mortality and fertility rates would ultimately result in low population growth across European societies (Coleman, 1996; Bégeot and Fernández Cordón, 1997; Coleman and Chandola, 1999). Following the postwar baby boom, demographic trends within the European Union (EU) were characterised by a sharp fall in fertility from the 1960s, together with a slowing down in the extension of life expectancy and the curtailment of inward migration (Eurostat, 2000, 2002a; European Commission, 2003). These combined trends have resulted in negative natural population growth and population ageing, which distinguish western Europe from countries in the less developed world. The Union, and more especially the enlarged Union of 25 countries, is not, however, a homogeneous mass with regard to demographic trends. Although the direction of change was broadly the same in the closing decades of the 20th century, considerable diversity could be observed both across and within regions, not only in the rate and pace of change but also in the reactions of policy actors to the challenges it poses.

Whether slow or negative population growth and population ageing are a cause, precipitating factor or outcome of changing family structures is a much debated question. Whatever the causal relationship, it is argued in this book that these various demographic phenomena are closely interwoven. In tracking and analysing the process of change, this and the next two chapters, which look at changing family forms and the family–employment relationship, follow the same structure. They begin by examining the problems associated with defining, conceptualising and measuring socio-demographic change from a comparative perspective, in the knowledge that published statistics provide no more than an incomplete snapshot at a given point in time and need to be treated with caution. The chapters then track demographic trends across EU member states, including the pre-accession countries in Central and Eastern Europe (CEE) and the two Mediterranean island states. Reference is made, in particular, to the implications of different waves of EU membership for European population size and social structure.