Observing the Number of Children with EU-SILC: A Quantification of Biases

Various fields of research increasingly use the European Union Statistics on Income and Living Conditions (EU-SILC) database because of its large country coverage, the availability of harmonized socioeconomic measures, and the possibility of merging partners. Its measures of the number of children risk being biased, however, because the questionnaire does not directly ask about the number of children ever born to a woman or man, and only those children who live in the parental household are observed. These limitations are problematic not only for demographic but also for socioeconomic analysis because family size and fertility behaviour are important determinants of income and living conditions. To raise awareness of this issue, we analyse the quality of the measure of the number of children in EU-SILC. For ten countries, we first quantify the bias in the reported number of children, distinguishing fertility measures by age and birth order. We then identify the socioeconomic profiles that are most subject to biased measures.