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Income and living conditions (ilc)

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National Reference Metadata in Single Integrated Metadata Structure (SIMS)

Compiling agency: [CH1] Office Federal de la Statistique (Swiss Federal Statistical Office)

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The European Union Statistics on Income and Living Conditions (EU-SILC) is a survey-based instrument aiming at collecting timely and comparable cross-sectional and longitudinal multidimensional microdata on income, poverty, social exclusion and living conditions on an annual basis. In addition, it collects module variables every three years, six years or ad-hoc new policy needs modules.

The EU-SILC instrument provides two types of data:

  • Cross-sectional data pertaining to a given time or a certain time period;
  • Longitudinal data pertaining to individual-level changes over time, observed periodically over four‐or more year rotation scheme (Annex III (2) of 2019/1700).

Information on housing conditions, part of income and material and social deprivation is collected at household level, while information on work, education, health and satisfaction in different areas of life is obtained for persons aged 16 and over. The core of the instrument consists of highly detailed income information, mainly collected at individual level, largely using registers.

3 December 2024

Statistical concepts and definitions for EU-SILC are specified in Regulation (EU) 2019/1700, Commission Implementing Regulation (EU) 2019/2181, and Commission Implementing Regulation (EU) 2019/2242. Additional information is available in the EU statistics on income and living conditions (EU-SILC) methodology and in the methodological guidelines and description of EU-SILC target variables.

Further details are provided in items 5, 15.1.1.1, 15.2.2 and 18.3.

Statistical units are private households and all persons living in these households who have usual residence in Switzerland.  Annex II of the Commission implementing regulation (EU) 2019/2242 defines specific statistical units per variable and specifies the, content of the quality reports on the organization of a sample survey in the income and living conditions domain pursuant to Regulation (EU) 2019/1700 of the European Parliament and of the Council.

The target population is permanent resident population living in private households (incl. non-permanent residents living in a household with at least one permanent resident). Private household means a person living alone or a group of persons who live together, providing oneself or themselves with the essentials of living.

The entire national territory is covered. 

Description of reference period used for incomes

Period for taxes on income and social insurance contributions

Income reference periods used

Reference period for taxes on wealth

Lag between the income ref period and current variables

 Social insurance contributions are calculated on the basis of income. Correspondingly, the reference period will be the same as for income, 2023

 Reference period for income variables is  2023

 Amounts relating to (income and wealth) taxation are from the 2023 calendar year

 As interviews took place between January and June 2024, the time lag between 2023 data and those corresponding to the time of the interview is 6 months at the most.

According to Reg. (EU) 2019/1700 Annex II, precision requirements for all data sets are expressed in standard errors and are defined as continuous functions of the actual estimates and of the size of the statistical population in a country or in a NUTS 2 region. For the income and living conditions domain, the estimated standard errors of the following indicators are examined according to certain parameters set:

  • · Ratio at‐risk‐of‐poverty or social exclusion to population;
  • · Ratio of at‐persistent‐risk‐of‐poverty over four years to population;
  • · Ratio at‐risk‐of‐poverty or social exclusion to population in each NUTS 2 region.

Further information is provided in section 13.2 Sampling error.

The data involves several units of measure depending upon the variables. Income variables are transmitted to Eurostat in national currency. For more information, see methodological guidelines and description of EU-SILC target variables.

Among the first stages, data are prepared to be used in the sample for next survey ( w1-3 ) in the "masterfile", with consolidated variables like age, sex, citizenship, marital status, highest educational level attained. Some rare missing values are imputed with a multiple imputation procedure. An arbitrary choice of the most plausible value is then made from the imputed values. This step is also essential for the following weightings and imputation procedures. AHV numbers are also searched for the new cohabitants, to enable a pairing with registers. 

Some individual information (consolidated) that does not change from year to year is recovered form previous years if the individual questionnaire has been filled in before. This is for example the case for variable height (PH110A, still asked yearly in the first individual interview), age at first job (PL190), year of immigration (RB031). Some household variables (HH010 , HH031) are also imported from the previous years if no change has been announced in the questionnaire. Furthermore, checks are conducted to verify, for example, that:

  • occupational status is consistent with ag;
  • family relationships are consistant with age and marital status (parents older than their children e.g.);
  • educational level stay equal or increase in time, and is consistant with age;
  • ISCO codes are consistant with NACE codes.

Register data from administrative sources are used when reliable and available at the time of statistical processing. This is the case for income variables First-pillar old-age pensions (PY100G) and Income received by people aged under 16 (HY110G). Employee cash or near-cash income (PY010G) is only surveyed through CATI in certain particular cases, but for most people the question is not asked and registers are used. Cash benefits or losses from self-employment (PY050G) is coming from register in most cases. 

Other income variables include some sub-components coming from registers: Survivor and disability pensions (PY110G and PY130G), Unemployment benefits (PY090G), Family/Children related allowances (HY050G), Social exclusion not elsewhere classified (HY060G) and Tax on income and social contributions (HY140G).

Full record imputation is used for Imputed rent (HY030)-collected each year in Switzerland, and Health insurance premium, which are included in the HY140G (see annex Estimation and imputation).

For the housing module, GEWO (Building and Flats) Register was used to build some variables. 

All other variables are collected through CATI/CAWI.

Annual

Due to late availability of register data, Switzerland is not subject to the same deadlines as the EU countries. First delivery is to be made by the end of September N+1, and final delivery by the end of November N+1. 

  • National publication of the results : planned on 16 Febrary 2026
  • End of field-work: 16 June 2024
  • First delivery of the data: 21 August 2025
  • Final delivery of the data: 24 October 2025
  • Months between the end of reference year N (2024) and the first delivery: 8
  • Months between the end of reference year N (2024) and the final delivery: 10

Not available.

A revision of the weightings occured in SILC14. Since then, the latest survey framework SRPH enabled more register data to be used. Longitudinal weightings could be revised from SILC17 on, when all waves had been drawn in the SRPH. These revision led to breaks in serie in SILC14 for the cross-sectional indicators, and a break in SILC17 for longitudinal indicators.

A new online survey method (CAWI) was introduced in 2023 for the SILC individual questionnaire, in parallel with the telephone survey method (CATI). The implementation of this survey method aims to increase response rates by offering online questionnaires to people who are more willing to respond via the Internet, as well as to people who no longer have a landline (ALTEL households, which have been increasing in our samples in recent years). It also reduces survey costs and increases flexibility for respondents.
The survey method can have an effect on the answer itself. In CATI, the respondent tends to adapt their answers so as to be perceived positively by the interviewer. Thus respondents may adjust their answers, unconsciously or not, to conform to social norms, the expec[1]tations of the interviewers and their own perception of social ideals. This phenomenon of social desirability, observed in telephone surveys, does not occur in CAWI. CAWI, on the other hand, can lead to a form of critical and negative venting. It is also less suitable for complex questions that can be explained to the person when they respond in CATI method. The effect of the survey method on the answer cannot be corrected by weighting.
In general, the main indicators showing a break in series following the introduction of the CAWI survey method are subjective evaluations such as satisfaction in different areas of life, trust in institutions and certain unmet needs for health care.