Methodology - Income and living conditions
EU-SILC is based on the idea of a common framework. The common framework is flexible in terms of data sources and sampling design although the use of existing data sources, whether they are surveys or registers, and the use of national sampling design is strongly encouraged.
As an illustration, the following sampling designs were used in 2007:
- Sampling of dwellings or addresses: Czechia, Germany, Spain, France, Hungary, Latvia, Luxembourg, Malta, the Netherlands, Austria, Poland, Portugal, Romania and United Kingdom.
- Sampling of households: Belgium, Bulgaria, Cyprus, Greece, Ireland, Italy, Slovakia and Switzerland.
- Sampling of individuals: Denmark, Estonia, Lithuania, Slovenia, Sweden, Finland, Iceland and Norway (all ‘register' countries except Lithuania).
The common framework defines a number of target objectives aimed at maximising the comparability of the information produced:
- Concepts and definitions;
- Guidelines and procedures;
- Harmonised lists of variables;
List of variables
EU-SILC comprises a list of target variables which are based on common guidelines. Each country may implement the most efficient solution from a national perspective to deliver the data corresponding to each variable. (For more details see Questionnaires under 'Quality') There are two kinds of variables in EU-SILC: the primary and secondary variables.
The primary variables are collected every year. These variables refer either to household or to individual (for person aged 16 and more) information and are regrouped into domains:
- At household level, four domains are covered: (1) basic data, (2) housing, (3) material deprivation and (4) income.
- The personal level is regrouped into five domains: (1) basic/demographic data, (2) education, (3) health, (4) labour and (5) income.
Household data (list)
Personal register (list)
Personal data (list)
Secondary variables are collected every five years or less frequently in the so-called ad-hoc modules. They include information either at household or personal level about specific topics.
Over time, the following topics have been addressed:
It is a pilot data collection, based on ESS agreement (for further details on ESS agreement see "Legislation"), of supplementary compulsory and optional variables on material deprivation implemented in 2013.
The classifications used in the production of EU-SILC results are based on international systems.
- The country codes conform to the ISO 3166 (International Organisation of Standardisation), with the exception of the United Kingdom which is coded as UK.
- The regional codes are the NUTS II and the corresponding statistical regions for the EFTA and Candidate Countries.
- The education variables (the level currently attended and the level reached) are based on ISCED 2011.
- The classification of occupation uses ISCO-88 (Com).
- The classification of economic activity uses NACE (Rev. 1.1 until 2007, Rev. 2 from 2008 onwards). See details on the transition between NACE Rev. 1.1 and Rev. 2.
For more details on the classification used please see RAMON, Eurostat's metadata server.