Attitudinal and behavioural indices of the Second Demographic Transition: Evidence from the last three decades in Europe

The Second Demographic Transition (SDT), which links ideational changes with demographic developments, is among the most prominent and debated theoretical frameworks in family demography. Yet, the existing attempts to operationalise it as a composite set of measures remain unevaluated. We evaluate two existing SDT indices: attitudinal and behavioural. We assess how strongly they have been linked to each other in the last three decades in Europe and test their consistency over time. Using four waves of the European Values Study and publically available demographic indicators for 23 European countries, we reconstruct, update, and evaluate the SDT indices. The attitudinal index measures postmaterialism, gender-egalitarianism, and religiosity. The behavioural index includes indicators of postponement, nonmarital childbearing, marriage, and divorce. The correlation between the attitudinal and behavioural indices is positive, but its strength varies substantially over time. The behavioural index is heavily determined by age at first marriage and at first birth, and only weakly correlated with marriage and divorce rates. The internal consistency of the attitudinal index is unstable over time. The strong link between the two SDT indices is driven by a correlation between the attitudinal index and two demographic postponement measures. As the strength of the correlation varies, conclusions based on cross-national data for a single year may be misleading. We show that the ideational and demographic changes posited by the SDT should not be treated as a package. Their operationalisation should take into account their multidimensionality. To facilitate future research, we provide ready-to-use indicator and index values used in the analysis.