Methodology for the Estimation of Annual population stocks by citizenship group, age and sex in the EU and EFTA countries

The paper addresses selected computational issues related to the challenge of dealing with poor statistics on international migration. Partial results of the on-going Eurostat-funded project on “Modelling of statistical data on migration and migrant population” (MIMOSA) are presented. The focus is on the data on population stocks by broad group of citizenship, sex and age. After a brief overview of the main problems with data on population by citizenship for 31 European countries (27 European Union countries, Iceland, Liechtenstein, Norway and Switzerland), a range of computational methods is proposed including cohort-wise interpolation, cohort-component projections, cohort-wise weights propagation and proportional fitting methods, as well as other, auxiliary methods. The algorithm for choosing the best method for estimating missing data on population stock by broad citizenship (nationals, foreigners – EU27 citizens, foreigners – non EU27 citizens), five-year age group (up to 85+) and sex on 1st January 2002–2006 is proposed and illustrated by examples of its application for selected countries.