The European Union Structure of Earnings Survey (SES) is conducted in all Member States of the European Union as well as candidate countries and countries of the European Free Trade Association (EFTA).

The national statistical institutes are responsible for selecting the sample, preparing the questionnaires, conducting the survey and forwarding the results to Eurostat in accordance with the common coding scheme as stipulated by the implementing arrangements prepared by Eurostat. The data are centrally processed by Eurostat.

The statistics of the SES refer to enterprises with at least 10 employees operating in all areas of the economy except public administration defined in Statistical classification of economic activities in the European Community (NACE).  Business activities, which are included in SES microdata are mentioned in NACE Rev. 2 sections B to S excluding O (NACE Rev. 1.1 sections C to O excluding L until reference year 2006). Information on public administration (NACE Rev. 1.1 Section L until 2006 and NACE Rev. 2 Section O from 2010) as well as enterprises with less than 10 employees is also available from some countries on a voluntary basis.

 Structure of Earnings Survey  was conducted on the basis of a two-stage sampling approach of enterprises or local units (first stage) and employees (second stage).

2002 and 2006

The methodology applied in the anonymisation of the SES microdata (‘scientific use files’) was as follows:

• Recodifying the categorical quasi-identifiers NACE, NUTS and SIZE of the enterprise in order to yield ratios between the number of sensitive combinations NACE-NUTS-SIZE (defined as those for which less than 3 enterprises exist in the member state's samples) and the total number of combinations in the SES lower than the threshold of 10% in a high majority of cases. The resulting codification mixes NACE sections, sub-sections or divisions and NUTS 0 or 1 levels as well as a maximum of 3 size classes (<50, 50 to 249 and 250+), depending on Member States;
• Removing Citizenship and performing global recoding on the age variable (2.2) to restrict its values to six intervals 14-19, 20-29, 30-39, 40-49, 50-59, 60+;
• Removing Citizenship and performing global recoding on the age variable (2.2) to restrict its values to six intervals 14-19, 20-29, 30-39, 40-49, 50-59, 60+;
• Ensuring an additional protection of employees using unconstrained individual ranking micro-aggregation for SES metric variables (absence days and earnings) by groups of (at least) 3 employees. This means that the latter variables are averaged for categories/combinations that include less than 3 employees in order to hide the information relating to individuals.

In addition, further specific anonymisation has been applied for some Member States. Finally, the Netherlands (2002 and 2006), Germany and Italy (all vintages) used their own national anonymisation methods. 

Council Regulation (EC) No 530/1999 of 9 March 1999 concerning structural statistics on earnings and on labour costs.
Commission Regulation (EC) No 1738/2005 of 21 October 2005 amending Regulation (EC) No 1916/2000 as regards the definition and transmission of information on the structure of earnings.
Commission Regulation (EC) No 72/2002 of 16 January 2002 implementing Council Regulation (EC) No 530/1999 as regards quality evaluation of structural statistics on earnings

The current legal framework enables access to anonymised microdata available at Eurostat only for scientific purposes (Commission Regulations (EU) 557/2013; (EC) No 1104/2006; (EC) No 1000/2007; Council Regulation 322/97), however the access is restricted to universities, research institutes, national statistical institutes, central banks inside the EU, as well as to the European Central Bank. Individuals cannot be granted direct data access.
http://ec.europa.eu/eurostat/web/microdata/overview

http://epp.eurostat.ec.europa.eu/portal/page/portal/microdata/documents/How_to_apply_for_microdata_access.pdf (the application form for research entities - page 4 - Word file

estat-microdata-access@ec.europa.eu

The comparability of the recent SES 2002 results and those from the reference year 1995 for the same geographical unit is for all countries reduced due to important changes as regards the set of mandatory variables (introduction of new variables, deletion of certain old variables), or the definition or breakdown of variables. For further details you may see the document "Summary of the quality reports" in the annex at the bottom of the page.

Comparability of the SES data across national borders may be affected by the use of different observation units and definitions, methods or classification schemes, i. e. by deviations between national and Community concepts. An overview on comparability problems reported to Eurostat can be found in the annex of the document "Summary of the quality reports".