Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
Turkish Statistical Institute (TURKSTAT) Devlet Mah. Necatibey Cad. No:114 06420 Çankaya / ANKARA
1.6. Contact email address
Confidential because of GDPR
1.7. Contact phone number
Confidential because of GDPR
1.8. Contact fax number
Confidential because of GDPR
2.1. Metadata last certified
13 August 2025
2.2. Metadata last posted
13 August 2025
2.3. Metadata last update
13 August 2025
3.1. Data description
The Turkish data for the STS indicators are obtained from administrative data of Social Security Institution (SSI) and Turkish Revenue Administration (TRA).
Number of Employees and Self-Employed Persons Index:
The number of employees and self-employed persons is defined as the total number of persons who work in the observation unit (inclusive of working proprietors, partners and unpaid family workers working regularly in the unit), as well as persons who work outside the unit who belong to it and are paid by it (e.g. sales representatives, delivery personnel, repair and maintenance teams).
Hours Worked by Employees Index:
Total number of hours worked by employees actually worked represents the aggregate number of hours actually worked for the output of the observation unit during the reference period. Self employed person's working hours are not covered.
Gross Wages-Slaries Index:
Gross Wages and Salaries are defined as the total remuneration, in cash or in kind, payable to all persons counted on the payroll, in return for work done during the accounting period, regardless of whether it is paid on the basis of working time, output or piecework and whether it is paid regularly.
3.2. Classification system
Nace Rev.2.
3.3. Coverage - sector
The activity coverage is Section B to N of NACE Rev. 2
3.4. Statistical concepts and definitions
Number of Employees and Self-Employed Persons Index:
The number of employees and self-employed persons is defined as the total number of persons who work in the observation unit (inclusive of working proprietors, partners and unpaid family workers working regularly in the unit), as well as persons who work outside the unit who belong to it and are paid by it (e.g. sales representatives, delivery personnel, repair and maintenance teams). It includes persons absent for a short period (e.g. sick leave, paid leave or special leave), and also those on strike, but not those absent for an indefinite period. It also includes part-time workers who are regarded as such under the laws of the country concerned and who are on the payroll, as well as seasonal workers, apprentices and home workers on the payroll. The number of persons employed excludes manpower supplied to the unit by other enterprises, persons carrying out repair and maintenance work in the observation unit on behalf of other enterprises, as well as those on compulsory military service.
Hours Worked by Employees Index:
Total number of hours worked by employees actually worked represents the aggregate number of hours actually worked for the output of the observation unit during the reference period.
The items included in total number of hours actually worked are:
regular working hours,
overtime, whether paid or unpaid,
hours worked during nights, Sundays or public holidays,
the time spent on tasks such as work preparation, preparing, maintaining and cleaning tools and machines and writing up work cards and reports,
time spent at the place of work during which no work is done owing to, for example, machine stoppages, accidents or occasional lack of work but for which payment is made in accordance with the employment contract,
short rest periods at the place of work, including tea and coffee breaks.
The items excluded in total number of hours actually worked are:
hours paid but not worked due to leave, sickness, accidents, strikes, lock outs, slack time, etc.,
time spent for meal breaks,
commuting between home and work.
Self-employed persons's working hours are not covered in labour input in construction.
Gross Wages-Slaries Index:
Gross Wages and Salaries are defined as the total remuneration, in cash or in kind, payable to all persons counted on the payroll, in return for work done during the accounting period, regardless of whether it is paid on the basis of working time, output or piecework and whether it is paid regularly.
Wages and salaries include the values of any social contributions, income taxes, etc. on behalf of the employee. Wages and salaries do not include social contributions payable by the employer.
The items included in gross wages and salaries are:
all gratuities, bonuses, extra payments,
severance payments, lodging, transport, cost-of-living, and family allowances,
tips, commission, attendance fees, etc. received by employees,
The items excluded in gross wages and salaries are:
social contributions payable by the employer
Data are recorded for the reference quarter.
3.5. Statistical unit
Reporting unit: Enterprise.
Observation unit(s): Enterprise.
3.6. Statistical population
Full enumeration.
3.7. Reference area
The whole country (Turkey) is covered. Activities outside the geographical coverage are not included in the data.
3.8. Coverage - Time
Time series for this indicator according to NACE Rev. 2 is available from 2005.
3.9. Base period
2021
Data are published in indices and yearly and quarterly percentage changes and are transmitted to Eurostat in the same way.
Quarter
6.1. Institutional Mandate - legal acts and other agreements
Legal basis: Turkish Statistical Law no. 5429, of 10 November 2005. Obligation on units to provide data: Compulsory surveys. Fines can be given in cases of non-response or deliberate reporting of wrong information according to the Statistical Law no. 5429. Planned changes in legal basis, obligation to respond and frame used: None Regulation (EU) 2019/2152 of the European Parliament and of the Council on European business statistics
6.2. Institutional Mandate - data sharing
Data are transmitted to Eurostat.
7.1. Confidentiality - policy
All statistics collected and published by TURKSTAT are governed by the Turkish Statistical Law no. 5429, of 10 November 2005.
Under the terms of the Statistical Law:
TURKSTAT has the independence to determine the methodology and release dates of statistics for which it is responsible.
Data are collected only for statistical purposes and confidentiality is assured.
The confidentiality of individual responses is guaranteed.
The TURKSTAT logo is used on all statistics published under the law.
The public dissemination of economic statistics is required.
7.2. Confidentiality - data treatment
If the number of statistical units in any cell of the data table formed by aggregating the individual data is less than three, or if one or two of the statistical units are dominant even if the number of units is three or more, the data in the concerned cell is considered confidential. Confidential data can be published only when combined with other data so as not to allow any direct or indirect identification. All measures to prevent any illicit access, use or revelation of the confidential data shall be taken by the institutions and organisations producing official statistics.
The confidential data compiled, processed and preserved for the production of official statistics cannot be delivered to any administrative, judiciary or military authority or person, can not be used for purposes other than statistics or as an instrument of proof. Confidential data can be accessed only by persons involved in the production of official statistics, to the extent that they are needed for performing their duties properly.
8.1. Release calendar
At the end of each year TURKSTAT publishes a release calendar providing the release dates for the coming year. The publication schedule can be accessed via TURKSTAT’s National Data Release Calendar.
The data are released to all interested parties by issuing the news release “Labour Input Indices”. Simultaneously, the news release is disseminated on the Turkish Statistical Institute (TURKSTAT) website.
There is no internal governmental access to data before their release to the public.
Series are transmitted to Eurostat at the same day with the press release. The transmission is done via EDAMIS by using GESMES coding system.
Quarterly national press release and quarterly data transmission to Eurostat
10.1. Dissemination format - News release
Labour Input Indices (Employment Index, Hours Worked in Index and Gross Wages-Salaries in Index) are disseminated in a special release with a brief explanation of the results each quarter.
The very detailed set of series is disseminated without explanation.
The news releases in English are available free of charge on Turkstat’s website.
10.2. Dissemination format - Publications
The results of the indices are published in the news release “Labour Input Indices”.
Series are transmitted to Eurostat at the same day with the press release. The transmission is done via EDAMIS by using GESMES coding system.
10.6. Documentation on methodology
Dissemination of documentation on methodology and sources used in preparing statistics: Methodology and sources used in statistical compilation are disseminated on the Turkish Statistical Institute (TURKSTAT) website.
Description of standard tables produced: Data are given as indices at the 2-digit NACE Rev. 2 level in the news release. The following indices are compiled:
Quarterly Employment Index (2021=100),
Quarterly Hours Worked Index (2021=100),
Quarterly Gross Wages-Salaries Index (2021=100).
10.7. Quality management - documentation
Not available
11.1. Quality assurance
All authorities that have statistical production in Turkey should obtain the necessities about quality of their data and disseminated statistical outputs within the official statistical principles according to the “Official Statistics Programme”. The Official Statistical Programme is monitored by Statistical Council of Turkey within the precidency of Turkstat.
The quality assurance concerns such as the contents of statistical data, production processes and service to data users. Official statistical principles with quality assurance framework covered can be found at TurkStat's Official Statistics Portal. Turkstat has also its own Board of Data Quality Control which monitores teh statistics produced according to the official statistical principles.
11.2. Quality management - assessment
The quality of statistics is assessed according to the principles of official statistics and Board of Data Quality Control.
Construction labour input indices are detected for criteria below;
Relevance: Data which indices are calculated from are checked for main activities with SBS (Structural business statistics), BR (Business Registers) and other surveys to be assured. Opininons are obtained in specific matters from users (public or private) about calculating indices and also technical support/advice from Eurostat stuff is taken.
Accuracy and reliability: Data source and results are regularly assessed and validated. Revisions to develop statistical process is analyzed regularly.
Timeliness and punctuality: Dissemination of press release and indices day and time announced to public at the beginning of the year which can be accessed at TURKSTAT’s National Data Release Calendar. Possible deviations from the publishing calendar, and a new date is notified to the public.
Comparability: All labour input indices are comparable with EU and other international regulations. Methodological studies are done with close cooperation between Eurostat.
Coherence: Eurostat and other international disclosure standards are covered.
12.1. Relevance - User Needs
Labour Input Indices are used by different national and international institutions and non-institutional users: Institutions: Ministries, National Central Bank, political institutions (e.g. parliament), local authorities International institutions: Eurostat, OECD, UN, ILO, IMF Social actors: Trade Unions Researchers and Educational Institutions Media Enterprises/businesses Internal users Public
12.2. Relevance - User Satisfaction
Not available.
12.3. Completeness
Data are compatible with EU regulations.
13.1. Accuracy - overall
Data source and results are regularly assessed and validated. Revisions to develop statistical process is analyzed regularly.
13.2. Sampling error
No sampling error, administrative data.
13.3. Non-sampling error
Not applicable / Not available
14.1. Timeliness
Timeliness: Quarterly Indices of Employment, Hours Worked and Gross Wages-Salaries are released as estimates at the end of the second month following the reference quarter.
14.2. Punctuality
The news release is published according to the announced release calendar.
15.1. Comparability - geographical
Whole Turkey is covered. Statistical information is comparable with EU countries.
15.2. Comparability - over time
Data on labour input are comparable over time. When significant changes are introduced (e.g. change of classification, base year or methodology), historical time series are recalculated as far back as it is reasonably possible. Time series according to NACE Rev. 2 are available from 2005 onwards.
15.3. Coherence - cross domain
Comparisons are made with relevant other sources like Labor Force Results and made with previous STS-values (previous month and year).
15.4. Coherence - internal
The total of Construction Input Indicators are consistent for gross data. Seasonally and calendar adjusted figures have been produced by using direct approach independently from the seasonal adjustment of its sub-series.
Not applicable / Not available
17.1. Data revision - policy
Revision is done due to the questionnaires which are late to index calculation and the errors which are made by the data providers. Revision is done also due to the updating of the base year and changes in statistical methods, concepts, definitions and classifications. For series;
Index values are revised for previous quarter in current quarter.
Index values are revised for each quarter in the end of year.
For the seasonal adjusted series;
Series are revised during the calculation of each quarter for last three years.
In the end of the year due to system and the methodology; the model structure of series, model parameters and outlier structure are revised if there is a change. After this process the series are revised.
In seasonal and calendar adjusted data; the model, filters, outliers and calendar variables are re-identified following the publication of the last bulletin of each year. Along the next year, parameters and factors are re-estimated in each bulletin period. The effects of this revision, which is sourced by the re-estimation of seasonality and calendar factors, is reflected on the data of last three years excluding the current year.
17.2. Data revision - practice
The news release indicates that the data are preliminary and are subject to revision. The preliminary results are final at the end of the reference year. Any major changes in methodology are announced at the time of the change and the data compiled using the revised methodology are released.
18.1. Source data
All enterprises (full enumeration) that declare their paid employees on Social Security Institution (SSI) Monthly Premium and Service Return and Turkish Revenue Administration (TRA) Withholding Tax Return records are included in the data. In the calculation of the hours worked, data of actual working hours of registered employees (paid workers) obtained from the Household Labor Force Survey conducted by TurkStat and registered employees (paid workers) data based on the administrative records.
18.2. Frequency of data collection
Quarterly
18.3. Data collection
Administrative data.
18.4. Data validation
Administrative data validated for statistical use using procedures for error checking.
18.5. Data compilation
Type of index: Laspeyres index method (weighted) with fixed base year is used.
18.6. Adjustment
Seasonal and calendar related effects prevent observing the general tendency of data because of their temporary characteristics. Therefore, identification of seasonal patterns of short term indicators plays crucial role in order to make reliable comparisons between consecutive periods
Method Used
The seasonal adjustment of Labor Input Indices is carried out using TRAMO-SEATS methodology. The software that is used for the application of this method is JDemetra+ developed by the National Bank of Belgium (NBB) in cooperation with the Deutsche Bundesbank and Eurostat in accordance with the Guidelines of the European Statistical System.
Seasonal Adjustment Process
Seasonal and calendar adjustment process of Labor Input Indices begins at the end of each year with the identification of the models of next year. This specified model structure is kept fixed throughout the year to adjust seasonally and/or calendar effects. At the end of the year, just like the previous year, specification of econometric estimation models for the following year is done. The identified process repeats itself in a cyclical manner each year. A substantial portion of Labor Input Indices contain seasonal and/or calendar effects.
Direct or Indirect Approach
Seasonally and calendar adjusted figures of Labor Input Indices are produced by indirect approach. Firstly the three digit NACE Rev2 classification individual subseries of Employment, Gross Wages-Salaries, Hourly Labour Cost Excluding Earnings and two digit Average Hours Worked subseries are seasonally adjusted. Then these series are used to derive seasonally and calendar adjusted Employment, Gross Wages-Salaries and Hours Worked Indices as well as Hourly Labor Cost Indices in NACE Rev2 two digit subseries, letters, MIGS and sector totals.
Revision Policy
Seasonal adjustment procedure is subject to revisions over time because of the re-estimation of seasonal component as new observations are added. These revisions are implemented on the data of the last three years excluding the current year.
Publication
Adjusted data has been published in 3 different ways.
“Calendar adjusted” data is derived from unadjusted data by removing calendar and holiday originated effects. Calendar adjusted data should be used in comparisons regarding the same month/period of the previous year.
“Seasonally adjusted” data is derived from unadjusted data by removing effects originating from seasonal effects. Seasonally adjusted data should be used in comparisons regarding the previous month/period.
If unadjusted data contains both calendar and holiday, and seasonal effects, “seasonally and calendar adjusted” data is derived by removing these effects. Seasonally and calendar adjusted data should be used in comparisons regarding the previous month/period.
Not applicable / Not available
The Turkish data for the STS indicators are obtained from administrative data of Social Security Institution (SSI) and Turkish Revenue Administration (TRA).
Number of Employees and Self-Employed Persons Index:
The number of employees and self-employed persons is defined as the total number of persons who work in the observation unit (inclusive of working proprietors, partners and unpaid family workers working regularly in the unit), as well as persons who work outside the unit who belong to it and are paid by it (e.g. sales representatives, delivery personnel, repair and maintenance teams).
Hours Worked by Employees Index:
Total number of hours worked by employees actually worked represents the aggregate number of hours actually worked for the output of the observation unit during the reference period. Self employed person's working hours are not covered.
Gross Wages-Slaries Index:
Gross Wages and Salaries are defined as the total remuneration, in cash or in kind, payable to all persons counted on the payroll, in return for work done during the accounting period, regardless of whether it is paid on the basis of working time, output or piecework and whether it is paid regularly.
13 August 2025
Number of Employees and Self-Employed Persons Index:
The number of employees and self-employed persons is defined as the total number of persons who work in the observation unit (inclusive of working proprietors, partners and unpaid family workers working regularly in the unit), as well as persons who work outside the unit who belong to it and are paid by it (e.g. sales representatives, delivery personnel, repair and maintenance teams). It includes persons absent for a short period (e.g. sick leave, paid leave or special leave), and also those on strike, but not those absent for an indefinite period. It also includes part-time workers who are regarded as such under the laws of the country concerned and who are on the payroll, as well as seasonal workers, apprentices and home workers on the payroll. The number of persons employed excludes manpower supplied to the unit by other enterprises, persons carrying out repair and maintenance work in the observation unit on behalf of other enterprises, as well as those on compulsory military service.
Hours Worked by Employees Index:
Total number of hours worked by employees actually worked represents the aggregate number of hours actually worked for the output of the observation unit during the reference period.
The items included in total number of hours actually worked are:
regular working hours,
overtime, whether paid or unpaid,
hours worked during nights, Sundays or public holidays,
the time spent on tasks such as work preparation, preparing, maintaining and cleaning tools and machines and writing up work cards and reports,
time spent at the place of work during which no work is done owing to, for example, machine stoppages, accidents or occasional lack of work but for which payment is made in accordance with the employment contract,
short rest periods at the place of work, including tea and coffee breaks.
The items excluded in total number of hours actually worked are:
hours paid but not worked due to leave, sickness, accidents, strikes, lock outs, slack time, etc.,
time spent for meal breaks,
commuting between home and work.
Self-employed persons's working hours are not covered in labour input in construction.
Gross Wages-Slaries Index:
Gross Wages and Salaries are defined as the total remuneration, in cash or in kind, payable to all persons counted on the payroll, in return for work done during the accounting period, regardless of whether it is paid on the basis of working time, output or piecework and whether it is paid regularly.
Wages and salaries include the values of any social contributions, income taxes, etc. on behalf of the employee. Wages and salaries do not include social contributions payable by the employer.
The items included in gross wages and salaries are:
all gratuities, bonuses, extra payments,
severance payments, lodging, transport, cost-of-living, and family allowances,
tips, commission, attendance fees, etc. received by employees,
The items excluded in gross wages and salaries are:
social contributions payable by the employer
Data are recorded for the reference quarter.
Reporting unit: Enterprise.
Observation unit(s): Enterprise.
Full enumeration.
The whole country (Turkey) is covered. Activities outside the geographical coverage are not included in the data.
Quarter
Data source and results are regularly assessed and validated. Revisions to develop statistical process is analyzed regularly.
Data are published in indices and yearly and quarterly percentage changes and are transmitted to Eurostat in the same way.
Type of index: Laspeyres index method (weighted) with fixed base year is used.
All enterprises (full enumeration) that declare their paid employees on Social Security Institution (SSI) Monthly Premium and Service Return and Turkish Revenue Administration (TRA) Withholding Tax Return records are included in the data. In the calculation of the hours worked, data of actual working hours of registered employees (paid workers) obtained from the Household Labor Force Survey conducted by TurkStat and registered employees (paid workers) data based on the administrative records.
Quarterly national press release and quarterly data transmission to Eurostat
Timeliness: Quarterly Indices of Employment, Hours Worked and Gross Wages-Salaries are released as estimates at the end of the second month following the reference quarter.
Whole Turkey is covered. Statistical information is comparable with EU countries.
Data on labour input are comparable over time. When significant changes are introduced (e.g. change of classification, base year or methodology), historical time series are recalculated as far back as it is reasonably possible. Time series according to NACE Rev. 2 are available from 2005 onwards.
