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.
Producer Price Index aims to measure producer price changes in a certain period for the products sold by domestic producers domestically.
Non Domestic Producer Price Index aims to measure producer price changes of products exported abroad by domestic producers in a certain period.
Definitions of Data:
Producer Price Index (PPI) is a measure of the change in prices of goods sold domestically by producers during a specific reference period.
Non-Domestic Producer Price Index (ND-PPI) is a measure of the change in the export prices (FOB) of goods sold as output by domestic producers into foreign countries in a given reference period.
3.2. Classification system
CPA 2008
3.3. Coverage - sector
Activities covered:
Domestic-PPI covers the sections of B to E. Divisions 05,06,07,08,10, 11,12, 13, 14, 15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,35,36 of CPA 2008, excluding Groups 07.21, 24.46, 25.4, 30.1 ,30.3, 30.4, 37 and 38.The PRODCOM classification is used. For non-domestic PPI, it includes sections B and C.
Types of prices: For domestic-PPI, prices are cash prices, excluding VAT and all relevant taxes and for non-domestic PPI, prices are FOB prices excluding VAT and all relevant taxes.
3.4. Statistical concepts and definitions
Index formula: Laspeyres.
Sources of weights: Data are compiled from survey results. Different searches (Annual Industrial Product Statistics, Industrial Production and Turnover Statistics, GNP data,) are made depending on the sectors.
Prices collected: For domestic-PPI, prices are cash prices, excluding VAT and all relevant taxes and for non-domestic PPI, prices are FOB prices excluding VAT and all relevant taxes.
3.5. Statistical unit
Reporting unit: Kind of activity unit.
Observation unit(s): Enterprise and kind of activity unit.
3.6. Statistical population
The population consists of more than 7,000(d-PPI) and 4,000(nd-PPI) enterprises in 701(d-PPI) and 617(nd-PPI) CPA subcategories, in the sectors within the scope, whose production is in Turkey in 2024 and which has a significant share in the domestic sales value.
3.7. Reference area
Geographical area covered: Türkiye.
3.8. Coverage - Time
D-PPI series are backcasted to 1982.
Time series for nd-PPI is available from 2010.
3.9. Base period
Base year: 2021
Indices and rate of changes.
Reference period is monthly.
6.1. Institutional Mandate - legal acts and other agreements
At European Level:
European Business Statistics (EBS) Regulation (EU) 2019/2152 on 27 November 2019, followed by the Commission Implementing Regulation 2020/1197
At National Level:
The compilation and dissemination of the data are governed by the Turkish Statistical Law No. 5429 of November 10, 2005. The purpose of this law is to determine basic principles and standards concerning the production and organisation of official statistics; and to regulate the formation, duties, and authorities of the Turkish Statistical Institute (TurkStat) which is to compile and assess data and information, produce, publish, and disseminate statistics on the areas that country needs, and to ensure coordination among institutions and organizations that are involved in the statistics process prescribed in the Official Statistics Programme (Article 1). The Official Statistics Programme establishes the framework for official statistics that shall be produced on subjects required at national and international level. Censuses and surveys are carried out within the framework of this Programme (Article 3).
6.2. Institutional Mandate - data sharing
Data of indices are transmitted to Eurostat
Upon request, index values are shared with all international and national institutions and researchers within the framework of data privacy 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
Confidentiality: 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.
8.1. Release calendar
The data release calendar for statistical outputs is prepared on an annual basis and it is publicly announced on the National Data Release Calendar section of the website.
8.2. Release calendar access
Publication dates and times of the press releases published by the Turkish Statistical Institute are available at National Data Release Calendar.
8.3. Release policy - user access
The principles, standards and procedures regarding the publication and dissemination of statistics produced by Turkish Statistical Institute are determined by the Publication and Dissemination Board. In order to ensure that statistics are delivered to users in accordance with the principles of confidentiality and equal access, and in an accurate, reliable, consistent, timely, and transparent way, the publishing dates of the press releases are determined within the framework of the Directive on the Procedures and Principles Regarding the Working Calendars of the Presidency of the Turkish Statistical Institute and announced to the public via the institutional website at the beginning of each year.
Monthly.
10.1. Dissemination format - News release
Press Releases:
Monthly Bulletin of Domestic Producer Price Index (D-DPPI)
Monthly Bulletin of Non-Domestic Producer Price Index (ND-DPPI)
The results of the index are published in a press release (Yurt İçi Üretici Fiyat Endeksi Ay/Yıl Haber Bülteni/ Press Release DOMESTIC PRODUCER PRICE INDEX Month/Year; Yurt Dışı Üretici Fiyat Endeksi Ay/Yıl Haber Bülteni/ Press Release NON-DOMESTIC PRODUCER PRICE INDEX Month/Year), in Turkish and English, and they are disseminated in the publication "Monthly Bulletin of Statistics" in English and in Turkish. There are also statistical tables and metadata which are published.
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 CoP is available on the Eurostat'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.
ISO 9001:2015 Quality Management Documentation
Quality-related documents were created within the scope of the ISO 9001:2015 Quality Management standard. Procedures, guides, instructions, plans, lists, and forms are included in the quality management system along with the standard coding system. There is a "Document Control Procedure" for the creation and updating of the documents. In addition, all studies are detailed on the basis of the articles of the standard in the "Quality Handbook", prepared within the scope of the ISO 9001:2015 Quality Management standard.
11.1. Quality assurance
TurkStat Quality Policy
TurkStat is committed to implementing a quality policy based on the European Statistics Code of Practice (ES-CoP), the European Statistical System Quality Assurance Framework (ESS-QAF), and other internationally recognized best practices determined by the European Statistical Office (Eurostat). In this context, TurkStat strictly adheres to and implements quality standards in statistical production processes by adopting the principle of continuous improvement and excellence in accordance with the ISO 9001:2015 Quality Management System Standard.
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.
ISO 9001:2015 Quality Management System
TurkStat is certified by the “ISO 9001:2015 Quality Management System” standard. TurkStat implements a holistic quality management system by fulfilling all the necessary requirements of the standard.
11.2. Quality management - assessment
Quality Monitoring and Assessment Tool (QMAT)
TurkStat aims to increase the quality of statistics by evaluating the compliance of official statistics produced with quality principles and standards based on European Statistics Practice Principles (Code of Practice-CoP). As a result of the quality assessment carried out with QMAT, areas open to improvement are determined and improvement action plans are created. The actions scheduled in the improvement action plan are regularly monitored to ensure continuous improvement in the quality of official statistics.
12.1. Relevance - User Needs
There are sections on the website of our institution for users who want to access both general and detailed information. After selecting the topic interested in from the "Subcategories" part of the "Statistics" section and clicking on the "Search" button, "Press Release", "Statistical Tables", "Databases", "Reports" and "Metadata" contents can be reached.
Data at international and regional level can be accessed through the "Regional Statistics", "Provincial Indicators", "International Selected Indicators", and "Turkstat Library" applications in the "E-Services" section.
Data requests which cannot be replied are compiled regularly and data production process are addressed in the light of this information.
If the requested data cannot be accessed from the website; it is possible to make a data request via https://ty.tuik.gov.tr web address.
12.2. Relevance - User Satisfaction
Statistics produced by the Turkish Statistical Institute are presented to users through various channels, and a number of studies are carried out to increase service quality and meet user needs. The user satisfaction survey, which is one of these studies, is conducted through the corporate website in order to determine the profile, needs, and expectations of the users. The results of the survey are reported annually.
d-PPI and nd-PPI are compliant with EBS-Regulation.
13.1. Accuracy - overall
Received PPI (Producer Prıce Index) results are analyzed, looking for errors, which may affect the final results. Outliers are determined by using SAS programme, and some computings are made by using excel and SAS together.
13.2. Sampling error
It is a sample survey. The size of statistical error is not calculated. Cutoff sampling method is used.
13.3. Non-sampling error
Response rate:90-99% (unweighted).
Actions to speed up or increase the rate of response: E-mail and phone reminders.
14.1. Timeliness
The publication date of D-PPI is the 3rd day after the end of the reference period. For Non Domestic Producer Price Index, the first publication is the 20th day from the end of the reference period.
14.2. Punctuality
The news releases are published according to the announced release calendar.
15.1. Comparability - geographical
d-PPI and nd-PPI are comparable to the EU. Methodological studies are carried out in close cooperation with Eurostat. The same statistical concepts are applied to all of Türkiye. There are no geographical differences.
15.2. Comparability - over time
There is no break until the series of 2005. After 2005, the chained laspayres index formula was started to use for d-PPI and for nd-PPI the chained laspayres index formula was started to use after 2014.
15.3. Coherence - cross domain
Dissemination of information that support statistical cross-checks and provide assurance of reasonableness:Other data sets (but only limited cross-checks are possible): An ad hoc comparison is made for d-PPI with the CPI.
For nd-PPI, comparison with the price trends in industry, in external trade, consumer prices and the world market prices.
15.4. Coherence - internal
PPI is internally coherent. Lower level price indices are aggregated to the higher level indices and the total.
The average time spent by respondents to fill statistical report is 15 minutes.
17.1. Data revision - policy
Data are not subject to revision.In case of revision the 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 : Provision of information about revision and advance notice of major changes in methodology.
There was no revision during the year of reference. MAR/MR =0
18.1. Source data
Type of source: Statistical survey
Frame on which the source is based: The frame used for sampling and derivation of weights is based on the results of the Industrial Production Survey for d-PPI. ProdCom and foreign trade statistics are used as data source for nd-PPI.
Sample or census: Sample
Criteria for stratification: Only the leading products (above 80% of the production value of the whole Group) are included. Observation units are selected such that the sum of their sale value covers 80% of the relevant product’s total sale value (ProdTR).
Threshold values and percentages: Only the leading products (above 80% of the production value of the whole Group) are included. Observation units are selected such that the sum of their sale value covers 80% of the relevant product’s total sale value (ProdTR).
Frequency of updating the sample: Yearly.
18.2. Frequency of data collection
Monthly.
18.3. Data collection
The data used in the Domestic Producer Price Index calculation is obtained from the Producer Price Statistics Monthly Questionnaire. The average of the prices of the 5th, 15th and 25th days in the reference month is compiled. Monthly average prices are used for products such as coal, electricity, crude oil and natural gas.
The data used in the calculation of the Non-Domestic Producer Price Index is obtained from the Foreign Producer Price Statistics Monthly Questionnaire via web. Monthly average prices of exports are compiled.
18.4. Data validation
Reporting units and regional offices control data entry through edits received through the data entry program.
Verification of prices: Experts analyze reported price changes and their reasons within the framework of comments and openings. Region offices remain in close contact with the reporting units.
Processing and analysis of data: Price changes are compared with the previous periods and in CPA categories. Reasons and comments provided by reporting units and region offices are examined and compared with other local units' and international market . Calculations and checks for estimates and quality changes are controlled by sector experts. The influence of price changes in item level and groups on the development of the index is analyzed. Checks are made on the weights and the correctness of the calculations.
Once a year, the weighting structure is compared with the most recent data.
18.5. Data compilation
Estimate for missing values:
Average price change for same respondent units
6-digit CPA weighted Average price change
If not available other unit in 6-digit of CPA; 4-digit CPA weighted average price change
Repeating previous period prices
Estimates provided by the responding unit using model price and main input component pricing methods
Methods for quality change:
Overlapping prices
Matched models only
Option prices
Link to show no change
Using average price change for same respondent units
Using 6-digit CPA weighted average price change
If not available other unit in 6-digit of CPA; using 4-digit CPA weighted average price change
Type of index: Chained Laspeyres
Source of weights: Compiled in survey results. According to different sources and sectors (Annual Industrial Product Statistics, Industrial Production and Industrial Product Statistics, Industrial Production and Turnover, National Income, Foreign Trade Export Data). Weights are calculated.
Planned changes in production methods: None.
18.6. Adjustment
No working day or seasonal adjustment is foreseen. There is only one calculation method used for compiling the indices.
Not available.
Purpose of the Studies:
Producer Price Index aims to measure producer price changes in a certain period for the products sold by domestic producers domestically.
Non Domestic Producer Price Index aims to measure producer price changes of products exported abroad by domestic producers in a certain period.
Definitions of Data:
Producer Price Index (PPI) is a measure of the change in prices of goods sold domestically by producers during a specific reference period.
Non-Domestic Producer Price Index (ND-PPI) is a measure of the change in the export prices (FOB) of goods sold as output by domestic producers into foreign countries in a given reference period.
24 June 2024
Index formula: Laspeyres.
Sources of weights: Data are compiled from survey results. Different searches (Annual Industrial Product Statistics, Industrial Production and Turnover Statistics, GNP data,) are made depending on the sectors.
Prices collected: For domestic-PPI, prices are cash prices, excluding VAT and all relevant taxes and for non-domestic PPI, prices are FOB prices excluding VAT and all relevant taxes.
Reporting unit: Kind of activity unit.
Observation unit(s): Enterprise and kind of activity unit.
The population consists of more than 7,000(d-PPI) and 4,000(nd-PPI) enterprises in 701(d-PPI) and 617(nd-PPI) CPA subcategories, in the sectors within the scope, whose production is in Turkey in 2024 and which has a significant share in the domestic sales value.
Geographical area covered: Türkiye.
Reference period is monthly.
Received PPI (Producer Prıce Index) results are analyzed, looking for errors, which may affect the final results. Outliers are determined by using SAS programme, and some computings are made by using excel and SAS together.
Indices and rate of changes.
Estimate for missing values:
Average price change for same respondent units
6-digit CPA weighted Average price change
If not available other unit in 6-digit of CPA; 4-digit CPA weighted average price change
Repeating previous period prices
Estimates provided by the responding unit using model price and main input component pricing methods
Methods for quality change:
Overlapping prices
Matched models only
Option prices
Link to show no change
Using average price change for same respondent units
Using 6-digit CPA weighted average price change
If not available other unit in 6-digit of CPA; using 4-digit CPA weighted average price change
Type of index: Chained Laspeyres
Source of weights: Compiled in survey results. According to different sources and sectors (Annual Industrial Product Statistics, Industrial Production and Industrial Product Statistics, Industrial Production and Turnover, National Income, Foreign Trade Export Data). Weights are calculated.
Planned changes in production methods: None.
Type of source: Statistical survey
Frame on which the source is based: The frame used for sampling and derivation of weights is based on the results of the Industrial Production Survey for d-PPI. ProdCom and foreign trade statistics are used as data source for nd-PPI.
Sample or census: Sample
Criteria for stratification: Only the leading products (above 80% of the production value of the whole Group) are included. Observation units are selected such that the sum of their sale value covers 80% of the relevant product’s total sale value (ProdTR).
Threshold values and percentages: Only the leading products (above 80% of the production value of the whole Group) are included. Observation units are selected such that the sum of their sale value covers 80% of the relevant product’s total sale value (ProdTR).
Frequency of updating the sample: Yearly.
Monthly.
The publication date of D-PPI is the 3rd day after the end of the reference period. For Non Domestic Producer Price Index, the first publication is the 20th day from the end of the reference period.
d-PPI and nd-PPI are comparable to the EU. Methodological studies are carried out in close cooperation with Eurostat. The same statistical concepts are applied to all of Türkiye. There are no geographical differences.
There is no break until the series of 2005. After 2005, the chained laspayres index formula was started to use for d-PPI and for nd-PPI the chained laspayres index formula was started to use after 2014.
