Statistics on Income and Living Conditions (SILC)

SILC (Statistics on Income and Living Conditions) is a representative survey of households in Switzerland. This instrument aims at studying poverty, social exclusion and living conditions on the basis of indicators that are comparable at the European level.

This yearly survey (from January to June) is carried out through telephone interviews (CATI). The persons who participate in the survey are interviewed for several years. This setting aims at describing the important stages in individual trajectories and at studying changes in living conditions.

Fact sheet

Frequently asked questions (FAQ)

What topics are covered by the SILC survey?

Questions are asked on the following topics:

In addition to the basic questionnaire, one or several specific topics are considered every year:

2007: Housing conditions
2008: Over-indebtedness and financial exclusion
2009: Material deprivation
2010: Intra-household sharing of resources
2011: Intergenerational transmission of disadvantages
2012: Housing conditions
2013: Well-being/material deprivation/indebtedness/cultural participation
2014: Material deprivation
2015: Social and cultural participation/material deprivation/fortune
2016: Access to services
2017: Health and children’s health /indebtedness
2018: Well-being/housing difficulties/material deprivation/fortune
2019: Intergenerational transmission of disadvantages
2020: Wealth / indebtedness / consumption / labour
2021: Children / Living arrangements and conditions of children within separated or blended families / Covid-19

You will find the current SILC survey questionnaires here (available in French, German and Italian).

Why does the FSO use register information?

The FSO is aware of the burden involved in responding to surveys for the Confederation. We make every effort to reduce this burden to a minimum without compromising our information mandate. Consequently, the Federal Council and Parliament have decided that information that is already available in the registers does not have to be provided in surveys (Federal Statistics Act of 9th October 1992, RS 431.01). Specific surveys are still necessary for all important information that is not available in the registers. For example, the SILC survey collects information on topics such as health, satisfaction, housing conditions, quality of life and childcare.

The following information is usually taken from registers and used for the SILC survey:

Household contact information such as address and telephone number.
Demographic information on the households selected such as sex, age, nationality and civil status.
Information on certain income sub-components such as 1st pillar pensions, unemployment insurance, salaries subject to social insurance contributions and family allowances.

How are the questions decided on?

SILC is a European survey that is coordinated by Eurostat. The information to be collected is specified in the European Commission's ordinances and in great detail in a reference document called "DocSILC065 Methodological guidelines and description of EU-SILC target variables". This makes it possible to compare results in over 30 European countries. Some questions, for example on the existence of a flushing toilet for sole use of household, may seem unnecessary in Switzerland but may be more relevant in other European countries.

To satisfy the needs of other sections of the FSO or other federal bodies, some additional questions may be added to the European questions.

How can I obtain the results of the SILC survey?

The main results of the SILC survey can be consulted online on the FSO website (available in French, German and Italian):

These data are available for all years from 2007, the start of the SILC survey in Switzerland, and for a number of sociodemographic characteristics (e.g. age, sex, nationality, educational level, type of household).

Specific requests to obtain other results may be made to the SILC information service (info.silc@bfs.admin.ch).

Research institutions which would like to carry out special analyses or more detailed analyses of data from the survey may make an official request to obtain primary data (microdata). Although these data are completely anonymous and the protection of personal data is guaranteed, it is nonetheless essential that users sign a data protection agreement.

What is the difference between longitudinal and transversal data?

The SILC survey uses a rotating panel. The selected households are interviewed over several years and new households are selected and interviewed every year following the system described below.

For example, the 2020 SILC sample consists of roughly equal proportions of:

Households selected in 2017 that are in their fourth and final interview year (wave 4)
Households selected in 2018 that are in their third interview year (wave 3)
Households selected in 2019 that are in their second interview year (wave 2)
New households selected in 2020 that are in their first interview year (wave 1)

These groups are highlighted blue, by wave (W), in the diagram below.

Transversal data consist of the results obtained during the survey at time T, 2020 in the diagram above, grouping together the households in wave 1-2-3-4. Longitudinal data make it possible to analyse transitions between two years. The household data in wave 1 are therefore not included. Longitudinal data therefore make it possible to analyse the transitions (arrows) between:

Year T-1 (2019 in this example) and T (2020) for households having responded in T and T-1, i.e. around three quarters of the sample from year T
Year T-2 (2018) and T for two waves, i.e. half the sample in T
Year T-3 (2017) and T for one wave, i.e. a quarter of the sample in T

Even if some households are the same in two sets of consecutive transversal data, it is not possible to link these. This would require the use of a longitudinal weight that is not present in the transversal data. Furthermore, identifiers are subject to an anonymization process that makes it impossible to link data between two years.

What do primary data consist of and how can these be obtained?

Primary data are made up of data sheets from individual or household levels containing the Eurostat variables and some extra information for Switzerland, giving a total of roughly 800 variables. To guarantee the anonymity of the results, some variables are only available grouped into categories (e.g. by nationality: Swiss - foreign nationals) or limited to a maximum value (for example, age limit of 80 for persons aged over 80). Geographic data beyond major region level are not available as standard. Some more detailed geographic data may be obtained on request after evaluation by the FSO.

The cross-sectional primary data are available for every year from 2007 to 2020. Longitudinal data are available from SILC-2016 to SILC-2020.

Obtaining one or several primary data sets requires the signature of all users of a data protection agreement. If interested, requests may be made to the SILC information service (info.silc@bfs.admin.ch), together with the following information:

Research project title
Short description of the research project and reason for data use
Institution
Project managers
Surname, first name and address of all persons who will handle the data
Duration of the project and date until which the data will be used
Survey years for which the primary data are requested

This information will make it possible to consider the match between the SILC primary data and the project and will enable requests to be redirected if necessary. At the end of the contract, a confirmation of destruction of the data will be required.

First year based data set (cross-sectional or longitudinal) cost is fixed to 300 CHF, then 200 CHF for each additional year. For Federal affiliated or mandated organisms, data are free of charge. Students benefit from a preferential rate.

The EU-SILC primary data (see also "How are the questions decided on?") from all the countries are available from Eurostat free of charge but may only be obtained if the applicant is recognised as a research entity by Eurostat (further information can be found here).

European comparisons (EU-SILC)

The survey is also conducted each year in cooperation with the statistical office of the European Union (Eurostat) in about 30 countries throughout Europe (EU-SILC: „European Union Statistics on Income and Living Conditions"). Over 130 000 households and 270 000 persons take part in the survey. This means that the results can also be compared with those of other countries.

Links to the results and publications at European level are listed further below under "Further information" in the paragraph "Links".

Questionnaires

The questionnaires are available in French, German and Italian.

Further information

Most standard results of the SILC survey in Switzerland are available in French, German and Italian.

Other reports are available in French and German.