Fertility data for German speaking countries: what is the potential? Where are the pitfalls?

Kreyenfeld, M. R., Zeman, K., Burkimsher, M., Jaschinski, I.

Comparative Population Studies, 36:2-3, 349-380 (2011)



This paper provides an overview of fertility data for Germany, Austria and Switzerland. Particular attention is given to the availability of order-specific fertility data. We discuss the quality of data provided by the Statistical Offices, both birth registration data and censuses or microcensuses. In addition, we explore how social science surveys can be used to generate order-specific fertility indicators, and compare survey fertility estimates with estimates from vital statistics. Prior studies have shown that there is a “family bias” in most surveys, with the fertility of younger cohorts being overstated, because respondents with young children are easier to reach by interviewers. Our assessment of various types of surveys from the three countries mostly supports this notion. The “family bias” is most pronounced in family surveys in contrast to all-purpose surveys. Weighting data does not fully cure the “family bias”, which we attribute to the fact that the number of children is usually not considered a factor in calculating sample weights, as provided by the survey agencies and Statistical Offices. The confounding role of migration in the production of reliable and comparable fertility statistics is also discussed.