Methodology - Migration and Asylum

Methodology: International migration, citizenship

EU legislation in the field of demographic statistics obliges Member States to follow agreed concepts, definitions and breakdowns to ensure comparability of the demographic data they transmit to Eurostat.

European demographic statistics are internationally comparable as they follow the internationally agreed concepts and definitions adapted, where needed, to fulfil EU purposes.

Concepts and definitions

The main concept is the definition of international migration flows; the following definitions are applied:

  • Immigration: the action by which a person establishes his or her usual residence in the territory of a Member State for a period that is, or is expected to be, of at least 12 months, having previously been usually resident in another Member State or a third country.
  • Emigration: the action by which a person, having previously been usually resident in the territory of a Member State, ceases to have his or her usual residence in that Member State for a period that is, or is expected to be, of at least 12 months.
  • Usual residence: the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage or, in default, the place of legal or registered residence. The following persons alone are considered to be usual residents of the geographical area:

a) those who have lived in their place of usual residence for a continuous period of at least 12 months before the reference time; or

b) those who arrived in their place of usual residence during the 12 months before the reference time with the intention of staying there for at least one year.

  • Acquisition of citizenship: refer to those granted to persons having their usual residence in the territory of the Member State and who have acquired the citizenship of the Member State having previously held the citizenship of another Member State, of a third-country or having been stateless.

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Data sources

Following EU legislation in the field of international migration statistics, countries are free to choose the data sources that they have available nationally and the methodologies they consider fit-for-purpose in order to compile statistics for Eurostat while ensuring consistency and comparability.

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Most of the data sources used by the NSIs to compile migration data are administrative data sources, for example: Population registers, Health Insurance Registers, Tax Registers, Census 2011, estimation methods based on the Gross Domestic Product, residency index, using the mirror flows reported by partner countries, etc.. A few countries also use sample surveys to estimate the number of international immigrants and emigrants. For a more detailed description, please see the Eurostat and national metadata information below.

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  • Metadata of dataset Population with Eurostat and national information

European aggregates

Based on the national detailed figures on acquisition and loss of citizenship transmitted by the National Statistical Institutes, Eurostat derives geographical aggregates for the EU by applying common aggregation methods.

Aggregates expressed in absolute number are obtained from the arithmetical sum of components. When values are missing from the components, geographical aggregates are not calculated. Please note that the EU aggregates for the period 2010-2012 includes 2009 data for Romania.

Based on the detailed collected data, Eurostat icomputes some indicators, such as the share of EU, non-EU and foreign citizens who have acquired the citizenship of the reporting country.

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Article: Migration and migrant population statistics