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 and Transport Statistics” Department.
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
2, P. Volov Str.; 1038 Sofia, Bulgaria
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
22 April 2025
2.2. Metadata last posted
22 April 2025
2.3. Metadata last update
22 April 2025
3.1. Data description
Monthly Index of Services Production (ISP). ISP aims to follow the monthly change in the services production. ISP is compiled from deflated turnover value in the different service activities. For turnover of division I55 is used the VAT declarations. The indices are calculated at fixed base (2021=100). This information is suitable for tracing the current economic development and short-term forecasts.
The index data are presented in the following forms:
unadjusted
working-day adjusted
seasonally-adjusted.
3.2. Classification system
Classification of Economic Activities in the European Community (NACE Rev.2).
3.3. Coverage - sector
Sections H to N (with the exception of K, M701, M72 and M75) of NACE Rev.2. ISPs are calculated by economic activities at division and section level.
3.4. Statistical concepts and definitions
Production in short term business statistics is required as an index. The production volume index is the reference indicator for economic development and it is used in particular to identify turning points in economic development at an early stage. It should be presented in the form of a Laspeyres type index, comparing the current volume of production to the corresponding volume of production in the base period. Theoretical target of the production volume index:
In the view of business cycle statistics, own output should be measured. The terms ‘production’ or ‘output’ in the sense of business cycle statistics do not include inputs from other units.
The objective of the production volume index is therefore to measure changes in the volume of value added at close and regular intervals.
The changes in volume of value added measured should in general approximate the value added measured by the National Accounts concepts of value added.
The primary aim of compiling an ISP is to measure short-term movements in the production activity of industries in the service sector. The ISP should be defined as a weighted average of the real output of these industries, where the weights are based on their shares in the value added at factor cost of the services sector.The ISP measures the average change in the revenues from enterprises sales at constant prices. The reference period covered is the calendar month.
3.5. Statistical unit
Enterprise (Legal unit considered as enterprise).
3.6. Statistical population
Statistical population is a sample of enterprises making up 70% of the annual turnover of the enterprises in the sections H, I, J, L, M_STS and N.
3.7. Reference area
All regions of Bulgaria are covered.
3.8. Coverage - Time
Time series cover the period back to the first month of 2015.
3.9. Base period
2021=100
Indices (%).
Month.
6.1. Institutional Mandate - legal acts and other agreements
National Legal basis: National Law on Statistics (Article 20) states that all persons that manage or represent legal persons, are obliged to provide the National Statistical Institute and the Bodies of Statistics with reliable data when filling-in forms and questionnaires on surveys included in the National Statistical Programme, for which mandatory participation is provided.
EU Legislation: Regulation (EU) 2019/2152 of the European Parliament and of the Council of 27 November 2019 on European business statistics; Commission Implementing Regulation (EU) 2020/1197 of 30 July 2020 laying down technical specifications and arrangements pursuant to Regulation (EU) 2019/2152 and Regulation (EC) No 1893/2006 of the European Parliament and of the Council of 20 December 2006 establishing the statistical classification of economic activities NACE Revision 2.
Obligation on units to provide data: The survey is included into the National Statistical Programme – it is compulsory. The Law of statistics includes provisions relating to fines, which can be imposed for refusal, non-response and delay. They are laid down in specific Chapter 9 “Administrative and liability provisions” in article 52.
6.2. Institutional Mandate - data sharing
The indicator is transmitted monthly to the Eurostat.
7.1. Confidentiality - policy
Regulation (EC) No 223/2009 on European statistics (recital 24 and Article 20(4)) of 11 March 2009 (OJ L 87, p. 164), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.
Law on Statistics - The Law on Statistics includes provisions relating to data confidentiality and protection of secrecy, which are in compliance with the EU legislation and standard European practice. In the Law is stated that individual data received and collected at the time of statistical surveys shall be statistical confidentiality and shall be used only for statistical purposes. Individual data, obtained for the purposes of the statistical surveys, shall not be used as evidence to the bodies of the executive powers and the judicial authorities. Requirements, obligations and measures for data protection, as well as fines that can be imposed, are treated in separate chapters, namely Chapter 6 on "Protection of secrecy” and Chapter 9 on "Administrative penal provisions”.
7.2. Confidentiality - data treatment
Article 25 of the Law on Statistics specifies the criteria, according to which certain data cannot be made public or released – individual data, data which could be indirectly identified, as well as aggregations of less than three statistical units and/or when the relative share of one parameter is more than 85% of the total volume of this parameter for all population units.
Data, which according to the Law on statistics are confidential, are not published.
8.1. Release calendar
Indices of Services Productionare available 60 days after the end of the reference month.
The services production indexes from 2015 are posted on the website of NSI – in the on-line database Infostat.
10.4. Dissemination format - microdata access
Micro data are neither distributed nor provided to the users.
10.5. Dissemination format - other
The data is used in European aggregates as well as for dissemination of national data in Eurostat’s disseminations.
Special tables may be obtained from “Relation with users and e-services” department of NSI.
10.6. Documentation on methodology
The Methodology of Short-term Business Statistics, Interpretation and guidelines, contains a comprehensive set of recommendations on the compilation of the STS statistics. It is available at the link: Production Indices in Services | National statistical institute
10.7. Quality management - documentation
EBS Regulation EU 2019/2152 of the European Parliament and Regulation (EC) № 223/2009 of the European Parliament. To guarantee the quality of results, European statistics shall be developed, produced and disseminated on the bases of uniform standards and of harmonised methods. In this respect, the following quality criteria shall apply: relevance, accuracy, timeliness, puntuality, accessibility and clarity, comparability and coherence.
Member States shall provide the Commission (Eurostat) with reports on the quality of the data transmitted. The Commission (Eurostat) shall assess the quality of data transmitted and shall prepare and publish reports on the quality of European statistics.
The legal framework which regulates the production of data from Short-term business statistics states that statistical data compiled within the EU system must be of satisfactory quality and produced data are comparable between Member States. Verification of data is done through the process of conducting a statistical survey - from respondents, from experts in the regional statistical offices and from national experts in NSI. Identified inaccuracies and errors are removed timely and comparable data of good quality are provided.
The quality of statistical information and its production process is ensured by the provisions of the European Statistics Code of Practice. The documentation on quality management is available on the Internet: Quality | National statistical institute (nsi.bg)
11.2. Quality management - assessment
The quality assessment of the Index of production in services is based on quality requirements of the ESS (relevance, accuracy, timelines and punctuality, accessibility and clarity, coherence and comparability). The monitoring of the quality of the indicator, updating survey methodology, self-assessment of survey manager is carried out.
Monthly ISP measure changes in production between two different periods of time. This information is suitable for monitoring of current economic developments and short-term forecasts.
12.2. Relevance - User Satisfaction
Not available.
12.3. Completeness
Indices of services production are calculated at all levels of detail that are required by the Regulations concerning STS.
13.1. Accuracy - overall
Index of Production in Services is an indicator computed using Index of turnover in services and Deflators (relevant price indexes). Therefore the accuracy of ISP is determined by the punctuality of these two indicators (Turnover index in services and Producer prices in services), the description of which can be found in the metadata devoted to them.
13.2. Sampling error
The sample method used is Stratified random sample. First the enterprises are stratified by the level of activity (2 - or 3-digit codes of NACE Rev.2) and then at each activity they are stratified by turnover value. In each activity strata are defined four subsets depending on the turnover value. The first subset includes enterprises with the highest turnover and they are observed exhaustively. Enterprises from the second and third subsets are randomly sampled. The fourth subset includes enterprises with negligible or very low turnover, which are not surveyed monthly.
Extrapolation of the results to the population is made by using extrapolation coefficients which are based on the turnover of the selected units and total turnover in the particular strata.
The selection of statistical units falling in the sample and sampling errors are computed with SPSS.
Coefficient of variation is used as an indicator on precision. It is computed as a percentage.
Coefficient of variation for September of 2024:
Section/Division
Code
Coefficient of variation (%)
Transportation, storage and post
Н
0.2
Food service activities
I56
0.1
Information and communication
J
0.4
Real estate activities
L
0.2
Professional, scientific and technical activities (excl. M701, M72, M75)
M_STS
0.1
Administrative and support service activities
N
0.3
13.3. Non-sampling error
Errors made in the processing of the data are detected and removed by set arithmetic and logical controls of Information system “Business Cycles”.
Non-responder enterprises are performed imputation of data depending on the activity and stratum, using extrapolation coefficients.
The size-weighted unit response rate for September 2024 is 0.96.
The overall average response rate is around 95% in terms of the number of enterprises and about 95% when weighted with turnover. It varies significantly, depending on the principle activity and size of the enterprises.
14.1. Timeliness
Indices of services production are available 60 days after the end of the reference month.
Production indices in services are released at 11.00 o’clock of local time on the 65 days after the end of the reference month.
14.2. Punctuality
All deadlines are respected. There are no time lags between the actual delivery of the data to Eurostat and the target date when it should have been delivered.
15.1. Comparability - geographical
Indices of services production are representative for the whole country; they are not representative by regions of the country. NSI applies methodology, which is in line with international standards. In this sense, the comparability of the indicators across countries can be considered as very good.
15.2. Comparability - over time
Indices are presented as time series from the first month of 2015 according to NACE Rev.2., at base year 2021. Indexes are fully comparable over time.
15.3. Coherence - cross domain
Turnover indexes are compared with turnover indexes calculated on the base of annual Structural business statistics (SBS) survey. Also SBS is the source of weights for calculation the STS indicators. Data received from SBS and those receives from STS are coherent.
15.4. Coherence - internal
Higher aggregates are coherent with the lower levels. In the case of WDA and SA data, direct adjustment is used.
Information system ‘Business Cycles’ (IS BC) is for data collection, data editing and data processing of STS information. IS BC provides more efficient way of collecting data from enterprises.
Data for division I55 is collected from VAT declarations.
This new system and administrative data save recourses, reduce the burden of the reporting units and the quality of short term indicators is improved.
17.1. Data revision - policy
Data is revised for several reasons:
some of the deflators (price indexes) used have a quarterly periodicity and the deadline for their publication is longer than 60 days. This requires to apply thechniques for interpolation and prediction in order to receive monthly deflators
annual revisions come after the comparison with the annual turnover index, which is calculated on the bases of structural business statistics.
The same revision policy applied to data released nationally is applied and to the data transmitted to Eurostat.
All indices are recalculated when the base year is changed.
17.2. Data revision - practice
The data are revised once a year with the SBS data. Minor changes are made at the time when the revision is introduced and they are marked in footnotes in the relevant published tables.
Unadjusted data are revised for the last 2 years, seasonally adjusted and calendar adjusted data have revised since 2015.
The component indices are revised, the aggregates are also revised as they are compiled from the components. The revised data are published at the beginning of the calendar year on the NSI and IS INFOSTAT website. Data to be revised are marked as provisional.
Only final data are available on the NSI website.
Mean Absolute Revision (MAR) and Mean Revision (MR) are used as revision indicators. They are calculated on year-on-year growth rates for calendar adjusted data.
MAR and MR for calendar adjusted data for 2022-2024:
MR
MAR
H
-0.03
1.10
I
1.25
1.25
J
-0.13
5.77
L
0.18
7.42
M
-0.02
4.34
N
-0.02
1.11
18.1. Source data
The sources for compilation of ISPs in the service sector are : Turnover indices, based on a monthly statistical survey ‘Sales in industry, construction, trade and services’ and deflators (relevant combinations of SPPI, PPI, CPI, HPI, LCI, etc.).
VAT returns are used to estimate the indicator for division I55.
18.2. Frequency of data collection
Monthly.
18.3. Data collection
Sampling monthly survey for turnover indices and VAT declarations.
Interpolation, forecasting and direct use as deflators of different types of indexes derived from other statistical surveys.
18.4. Data validation
Data validation starts from the filling of the reports by respondents. Control of the data can be accessed from both the regional statistical offices and from experts in the National Statistical Institute. An information system ‘Business Cycles’ significantly contributes to the validation of the data submitted by set of arithmetic and logical controls.
The system carries out the statutory and warning controls. In case there are errors, it displays a warning dialog error in the report. The system does not allow completion of the report while are not corrected the errors. Data validation system incorporates many tools for data control, estimations and detail reports on data completeness. Subsequent analysis of the experts, a phone call for further clarification of data and elimination of disparities, minimize errors in the raw data and ensure accuracy of outputs at national level.
Validation of the output data - output data are verified at group level with regard to the previous month, with the same month of the previous year and also with regard to extreme values, if necessary data are validated at the level of statistical unit.
Before transmission to Eurostat, the structure of the data file and format is checked in detail.
18.5. Data compilation
At the lower level of aggregation (2-nd digit level of NACE Rev.2) indices calculation is made by direct deflating (dividing) of the turnover indices by the associated price indices.
At higher level of aggregation indices are calculated as weighted average - indices at lower levels are weighted with value added at factor cost in base year (2021).
18.6. Adjustment
Indexes of services production are published as:
unadjusted time series
working day adjusted time series
seasonally adjusted time series.
The software used for seasonal and working day adjustment is JDEMETRA+2.2.0 (TRAMO-SEATS).
The time series at 2-nd digit level of NACE Rev.2 of aggregation are seasonal and working day adjusted by applying the indirect method. At higher level of aggregation are calculated as weighted average.
Revisions of seasonally and working day adjusted data model updated once a year including revision of historical data.
More information about the seasonal adjustment in Annex.
Monthly Index of Services Production (ISP). ISP aims to follow the monthly change in the services production. ISP is compiled from deflated turnover value in the different service activities. For turnover of division I55 is used the VAT declarations. The indices are calculated at fixed base (2021=100). This information is suitable for tracing the current economic development and short-term forecasts.
The index data are presented in the following forms:
unadjusted
working-day adjusted
seasonally-adjusted.
22 April 2025
Production in short term business statistics is required as an index. The production volume index is the reference indicator for economic development and it is used in particular to identify turning points in economic development at an early stage. It should be presented in the form of a Laspeyres type index, comparing the current volume of production to the corresponding volume of production in the base period. Theoretical target of the production volume index:
In the view of business cycle statistics, own output should be measured. The terms ‘production’ or ‘output’ in the sense of business cycle statistics do not include inputs from other units.
The objective of the production volume index is therefore to measure changes in the volume of value added at close and regular intervals.
The changes in volume of value added measured should in general approximate the value added measured by the National Accounts concepts of value added.
The primary aim of compiling an ISP is to measure short-term movements in the production activity of industries in the service sector. The ISP should be defined as a weighted average of the real output of these industries, where the weights are based on their shares in the value added at factor cost of the services sector.The ISP measures the average change in the revenues from enterprises sales at constant prices. The reference period covered is the calendar month.
Enterprise (Legal unit considered as enterprise).
Statistical population is a sample of enterprises making up 70% of the annual turnover of the enterprises in the sections H, I, J, L, M_STS and N.
All regions of Bulgaria are covered.
Month.
Index of Production in Services is an indicator computed using Index of turnover in services and Deflators (relevant price indexes). Therefore the accuracy of ISP is determined by the punctuality of these two indicators (Turnover index in services and Producer prices in services), the description of which can be found in the metadata devoted to them.
Indices (%).
At the lower level of aggregation (2-nd digit level of NACE Rev.2) indices calculation is made by direct deflating (dividing) of the turnover indices by the associated price indices.
At higher level of aggregation indices are calculated as weighted average - indices at lower levels are weighted with value added at factor cost in base year (2021).
The sources for compilation of ISPs in the service sector are : Turnover indices, based on a monthly statistical survey ‘Sales in industry, construction, trade and services’ and deflators (relevant combinations of SPPI, PPI, CPI, HPI, LCI, etc.).
VAT returns are used to estimate the indicator for division I55.
ISPs are produced monthly and disseminated nationally.
Indices of services production are available 60 days after the end of the reference month.
Production indices in services are released at 11.00 o’clock of local time on the 65 days after the end of the reference month.
Indices of services production are representative for the whole country; they are not representative by regions of the country. NSI applies methodology, which is in line with international standards. In this sense, the comparability of the indicators across countries can be considered as very good.
Indices are presented as time series from the first month of 2015 according to NACE Rev.2., at base year 2021. Indexes are fully comparable over time.
