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.
Short Term Business Statistics Department / Turnover and Volume Indicators Group
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
Devlet Mahallesi Necatibey Caddesi 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
28 May 2025
2.2. Metadata last posted
28 May 2025
2.3. Metadata last update
28 May 2025
3.1. Data description
The main purpose of the Services Production Index (ISP) is to measure the short-term movements of production activities adjusted for price effects in the service sector, which is an important part of the economy. In other words, this index is defined as "the ratio of the volume of output produced in the service sector in a certain time period to the volume of output produced in the same sector in a certain base period.
3.2. Classification system
The indices are calculated according to the NACE Rev. 2 economic activity classification.
3.3. Coverage - sector
Following sectors are covered according to NACE Rev.2 classification for services production index;
section h – transportation and storage
section i – accommodation and food service activities
section j – information and communication
section l – real estate activities
section m – professional, scientific and technical activities
section n – administrative and support serviceactivities
3.4. Statistical concepts and definitions
The main purpose of the Services Production Index (ISP) is to measure the short-term movements of production activities adjusted for price effects in the service sector, which is an important part of the economy. In other words, this index is defined as "the ratio of the volume of output produced in the service sector in a certain time period to the volume of output produced in the same sector in a certain base period.
3.5. Statistical unit
Kind of activity unit
3.6. Statistical population
The statistical population comprises the enterprises which submit VAT declaration no.1 to the Revenue Administration in Türkiye.
3.7. Reference area
Türkiye
3.8. Coverage - Time
Series of services production index start from 2017.
3.9. Base period
2021=100
Indices and percentage changes
Monthly
6.1. Institutional Mandate - legal acts and other agreements
Legal basis: Statistical Law of TURKSTAT no. 5429, of 10th November 2005 is the legal basis of all statistics.
regulation (eu) 2019/2152 of the european parliament and of the council of 27 november 2019 on european business statistics, repealing 10 legal acts in the field of business statistics
commission implementing regulation (eu) 2020/1197 of 30 july 2020 laying down technical specifications and arrangements pursuant to regulation (eu) 2019/2152 on european business statistics, repealing 10 legal acts in the field of business statistics
6.2. Institutional Mandate - data sharing
Unadjusted, calendar adjusted and seasonal and calendar adjusted indices are transmitted to Eurostat. If requested, indices are shared with all international and national instutions and researchers under data confidentiality rules.
7.1. Confidentiality - policy
Data privacy and confidential data security regarding the statistics produced by Turkish Statistical Institute are guaranteed with the Turkish Statistical Law No. 5429 and the Regulation about Procedures and Principles of Data Privacy and Confidential Data Security of Official Statistics. Statistics are also prepared in accordance with the regulation published by the European Statistical Office (Eurostat) on March 11, 2009 with the number 223/2009 and the European Statistics Code of Practice, within the scope of harmonization with the European Union.The collection of data solely for statistical purposes and the confidentiality of the individual responses are guaranteed with the related legislation and regulations.
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. This is also disseminated on TurkStat's internet website Data Release Calendar
8.2. Release calendar access
Publication dates and times of the press releases published by the Turkish Statistical Institute are available at Data Release Calendar.
8.3. Release policy - user access
Simultaneous release to all interested parties:Data are released simultaneously to all interested parties by issuing the press release. The press release is subsequently&disseminated TurkStat's Internet website.
Identification of internal government access to data before release:There is no special application for this item.
Transmission to Eurostat and further use of the statistics: Data is transmitted to Eurostat.
Monthly.
10.1. Dissemination format - News release
Under the Statistical Law, any data product prepared under that law must be identified. Technical commentaries prepared by TurkStat accompany the news release.
Services Production Index news release can be accessed from the link below.
Micro-data access is not available to the public or private users.
10.5. Dissemination format - other
Information requests at national and international level are supplied.
Unadjusted, calendar adjusted and seasonal and calendar adjusted series are transmitted to Eurostat at the same day with the press release. The transmission is done via EDAMIS4.
10.6. Documentation on methodology
Methodology and sources used in statistical compilation are disseminated on the Turkish Statistical Institute (TurkStat) website. They can be found next to the press releases on metadata session.
European Statistics Code of Practice (CoP) are the quality principles and standards established by the European Union. CoP; It consists of 3 main sections: institutional environment, statistical processes and statistical outputs. There are 16 quality principles and 84 quality indicators under these principles. TurkStat carries out its activities in accordance with the CoP's quality principles and indicators. The Turkish translation of the CoP is available on the Institution's website.
Institutional Quality Reports
Institutional quality reports are prepared for annual studies. The relevant quality report can be accessed under the Metadata tab on the Statistics Data Portal.
11.1. Quality assurance
Quality Assurance Framework
The Quality Assurance Framework of the European Statistical System (ESS QAF) is a supporting document that aims to assist in the implementation of the European Statistics Code of Practice (CoP). It identifies possible activities, methods and tools that can provide guidance and evidence for the implementation of the CoP's indicators. TurkStat has determined its own quality assurance framework according to the QAF and shares it with all users on the TurkStat website. In line with the principles of the CoP, TurkStat quality assurance framework includes the studies, tools and legal regulations.
11.2. Quality management - assessment
Services Production Index is detected for below criterias;
relevance: getting opinions from users (public or private) about calculating indices, and taking technical support or advice from Eurostat staff
accuracy and reliability: data sources and results are regularly assessed and validated, and revisions to improve the statistical process are regularly analyzed
timeliness and punctuality: dissemination dates of press releases and indices are announced at the beginning of the year in the Data Release Calendar; any deviation from this calendar and the new publication date are shared with the public
comparability: all turnover indices are comparable with EU and other countries through methodological studies in close cooperation with Eurostat
coherence: Eurostat and other international disclosure standards are followed
12.1. Relevance - User Needs
The main users of statistical information are Eurostat, State institutions and agencies, international organisations, the media, research and business communities, students. The users' needs are satisfied without a breach of the confidentiality principle.
12.2. Relevance - User Satisfaction
Opinions from users (public or private) about calculating indices and technical support/advice from Eurostat staff always taken into consideration.
12.3. Completeness
Data are compliant with EU Regulations and national laws.
13.1. Accuracy - overall
Errors may be encountered due to incorrect coding of the activity at the source. Activity checks are made and enterprises that are found to have different activities from the activity specified in the source data are identified.
At the same time, enterprises whose turnover is incompatible with the series are questioned and their reasons are tried to be determined.
13.2. Sampling error
As all the enterprises that submit VAT declarations to the Revenue Administration are included in the index calculation, there is no sampling error.
13.3. Non-sampling error
Not available because of the usage of administrative sources.
14.1. Timeliness
The results are released on average t+44.
14.2. Punctuality
The news releases are published according to the announced release calendar.
15.1. Comparability - geographical
Services Production Index is comparable with EU and other countries. The same statistical definitions are applied to all of the countries.
15.2. Comparability - over time
There are no breaks in the series.
15.3. Coherence - cross domain
Comparisons are made with previous STS-values (previous month and year) and e-invoices data.
15.4. Coherence - internal
There is internal consistency.
Not available.
17.1. Data revision - policy
In the series which are not seasonal and calendar adjusted;
Index values are revised for previous two months with the release of current month,
Index values are revised for last two years at the end of the reference period.
In the series which are seasonal and calendar adjusted;
Index values are revised each month for last three years,
According to system and methodology, if there is a change; the model structure, parameters and outlier structure are modified in the end of each year. Therefore series are revised.
Same revision policy is applied nationally and in transmissions to Eurostat.
17.2. Data revision - practice
Provision of information about revision and advance notice of major changes in methodology: The press releases indicates that the data are preliminary and are subject to revision. The preliminary results are final at the end of two years. Any major changes in methodology are announced at the time of the change and the data compiled using the revised methodology is released.
Benchmarking: Not available
MR: 0,06
MAR: 0,12
18.1. Source data
The data source is administrative records. VAT (Value Added Tax) declarations no.1 received monthly from the Revenue Administration are used.
The data is received from the revenue administration via File Transfer Protocol (FTP). Then, verifications are made by the relevant IT unit and transferred to the database. The chained laspeyres index method is used. In the index calculation, turnover is deflated.
Although the Services Producer Price Index is mainly used in calculating the index, the following price indices are also used. The price indices in question are as follows;
consumer price index
domestic producer price index
non-domestic producer price index
agricultural products producer price index
construction cost index
18.2. Frequency of data collection
Monthly
18.3. Data collection
VAT declarations no.1 are compiled monthly from Revenue Administration.
The indices used as deflators are obtained from the relevant units.
18.4. Data validation
Micro data and indices are examined by using sql codes in TOAD.
18.5. Data compilation
After taking the data, they are analyzed by using TOAD and excel programs together. This program takes only the necessary fields from the declarations. Controls are made on the necessary fields. Incorrect or inconsistent data in the administrative record are corrected by using several data sources like e-invoices, etc. Imputation due to non-response is not performed. The business registers unit is informed in order to re-examine the main activities of newly opened businesses with high turnover.
Index type: The chained Laspeyres index method is used.
In calculating the relevant indices, turnover information obtained from VAT declarations no.1 received from the Revenue Administration are used as the data source. The services production index is calculated by the deflated turnover method. Using the results of the "Annual Turnover Survey by Products", the product structure of each sector is determined and deflators for these sectors are calculated with appropriate price data. In the services production index calculation, turnover values are deflated with these deflators at the four digit activity level. In the deflating process, the Service Producer Price Index is used 94.1% and the following price indices are used 5.9%.
consumer price index
domestic producer price index
non-domestic producer price index
agricultural products producer price index
construction cost index
Source of weighting: According to the NACE Rev. 2 classification, national accounts value added weights are used as weights in the calculation of each upper level indices. The own year's weight is used for the base year, and the previous year's (t-1) weights are used for each level.
18.6. Adjustment
Seasonal 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 Services Production Index is carried out using TRAMO-SEATS methodology. The software that is used for the application of this method is JDemetra+ 2.2.2 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.
Process of the seasonal adjustment
Seasonal and calendar adjustment process of Services Production Index 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 number of the subtitles of Services Production Index contain seasonal and calendar effects.
Direct or indirect seasonal adjustment
Seasonally and calendar adjusted figures of Services Production Index are produced by indirect approach. Firstly the second digit NACE Rev.2 classification individual subseries of Turnover Indices are seasonally adjusted and then aggregated to derive seasonally and calendar adjusted totals. The advantages of indirect approach are calculation of contributions to growth from components of main aggregates and retaining additivity.
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 is 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.
The main purpose of the Services Production Index (ISP) is to measure the short-term movements of production activities adjusted for price effects in the service sector, which is an important part of the economy. In other words, this index is defined as "the ratio of the volume of output produced in the service sector in a certain time period to the volume of output produced in the same sector in a certain base period.
28 May 2025
The main purpose of the Services Production Index (ISP) is to measure the short-term movements of production activities adjusted for price effects in the service sector, which is an important part of the economy. In other words, this index is defined as "the ratio of the volume of output produced in the service sector in a certain time period to the volume of output produced in the same sector in a certain base period.
Kind of activity unit
The statistical population comprises the enterprises which submit VAT declaration no.1 to the Revenue Administration in Türkiye.
Türkiye
Monthly
Errors may be encountered due to incorrect coding of the activity at the source. Activity checks are made and enterprises that are found to have different activities from the activity specified in the source data are identified.
At the same time, enterprises whose turnover is incompatible with the series are questioned and their reasons are tried to be determined.
Indices and percentage changes
After taking the data, they are analyzed by using TOAD and excel programs together. This program takes only the necessary fields from the declarations. Controls are made on the necessary fields. Incorrect or inconsistent data in the administrative record are corrected by using several data sources like e-invoices, etc. Imputation due to non-response is not performed. The business registers unit is informed in order to re-examine the main activities of newly opened businesses with high turnover.
Index type: The chained Laspeyres index method is used.
In calculating the relevant indices, turnover information obtained from VAT declarations no.1 received from the Revenue Administration are used as the data source. The services production index is calculated by the deflated turnover method. Using the results of the "Annual Turnover Survey by Products", the product structure of each sector is determined and deflators for these sectors are calculated with appropriate price data. In the services production index calculation, turnover values are deflated with these deflators at the four digit activity level. In the deflating process, the Service Producer Price Index is used 94.1% and the following price indices are used 5.9%.
consumer price index
domestic producer price index
non-domestic producer price index
agricultural products producer price index
construction cost index
Source of weighting: According to the NACE Rev. 2 classification, national accounts value added weights are used as weights in the calculation of each upper level indices. The own year's weight is used for the base year, and the previous year's (t-1) weights are used for each level.
The data source is administrative records. VAT (Value Added Tax) declarations no.1 received monthly from the Revenue Administration are used.
The data is received from the revenue administration via File Transfer Protocol (FTP). Then, verifications are made by the relevant IT unit and transferred to the database. The chained laspeyres index method is used. In the index calculation, turnover is deflated.
Although the Services Producer Price Index is mainly used in calculating the index, the following price indices are also used. The price indices in question are as follows;
consumer price index
domestic producer price index
non-domestic producer price index
agricultural products producer price index
construction cost index
Monthly.
The results are released on average t+44.
Services Production Index is comparable with EU and other countries. The same statistical definitions are applied to all of the countries.
