National statistical institute

"Short-term Business Statistics and Statistics of Transport" Department

Adelina Terezova

Chief expert

2, P. Volov Str.; 1038 Sofia, Bulgaria

ATerezova@nsi.bg

+359 2 9857 454

Construction Production Indices is an important short-term economic indicator of business, which purpose is to measure the monthly changes of the construction production between two comparable periods. This information can be used to analyze the current state of the construction activity in the country, as well as short-term forecast for its future development.

The indices - total and separately for building construction, civil engineering and specialized construction activities are calculated from information on actually hours worked in the construction. The rows of data are non-adjusted and seasonal and working day adjusted. Seasonal adjustment of monthly indices is a statistical method, which eliminates the seasonal component and working day adjustment is an adjustment for variations in monthly data, caused by calendar effects, different number of calendar and working days in the months, national holydays and outliers.

• Classification of Economic Activities (CEA-2008, for international use NACE.BG -2008);
•  Classification of types of constructions (CC) - the building construction includes construction of residential and no-residential buildings and civil engineering - infrastructure construction of roads, bridges, pipelines, power lines, telecommunication and other construction equipment.

Production Indices in section F of NACE.BG-2008, Construction - total and separately for building construction, civil engineering and specialized construction activities, according Classification of types of constructions (CC).

The purpose of Construction Production Indices is to show changes of the production in section Construction - total and separately for building construction, civil engineering and specialized construction activities, calculated on the base of hours worked, directly employed with construction works. Indices are calculated according to the regulations EC about Short Term Statistics.

The enterprises of section Construction, according to classification of Economic Activities (NACE.BG -2008).

The sample used is formed on the base of the information from annual reports of all construction enterprises which are observed exhaustively. The survey population includes the construction enterprises with more than 4 persons employed. The sample of the surveyed enterprises is formed 75% from turnover in construction.

National level: Data are aggregated and published total of R Bulgaria.

EC level: Eurostat are aggregated and published total of EC and by Member States.

The indices are published from January 2015 to the last month of the reference year.

All indices are calculated on the base 2021=100.

Indices, percentage changes (%).

Month

National Legal Basis: The Law on Statistics (Article 20) states that all persons that manage or present legal persons, are obligated 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.

The survey is included into the National Statistical Programme and it is compulsory for enterprises which are included in the sample of survey. The Law on 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.

EU Legislation:

• REGULATION (EC) No 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 (EC) No 2020/1197 of 30 July 2020 laying down technical specifications and arrangements pursuant to Regulation (EC) No 2019/2152 of the European Parliament and of the Council on European business statistics repealing 10 legal acts in the field of business statistics;

The data are transmitted to Eurostat together with the national publication.

•  Law on Statistics;
•  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.

Article 25 of the Law of Statistics defines the criteria by which can not be distributed or published statistical information. Statistical information which aggregates data about less than three statistical units or about a population in which the relative share of the value of a surveyed parameter of a single unit exceeds 85 percent of the value of such parameter for all units in the population.

Confidential data, accordance with the Law of statistics not publish. In order not to identify individual data using the method of suppression or aggregation of information disclosed.

The date for publication of statistical information is given in the Release Calendar presenting the results of the statistical surveys carried out by the National Statistical Institute, which is available on NSI website. The indices of construction production are published 37 - 40 days after the reference month.

Release calendar. 

The data are published on the NSI website, section Business statistics - Short-term Business Statistics - Monthly date in accordance with the Law on Statistics and the European Statistics Code of Practice respecting the professional independence and aimed at objectivity, transparency and equal treatment of all consumers.

Every month.

Press release of Indices Production Construction are published 37 - 40 days after the end of the reference month on the NSI website.

Brochure 'Bulgaria'

Data on indices of construction production are available to all users on the NSI website under the heading Statistical data - Business statistics - Short-term Business Statistics - Monthly data - Construction Production Indices or in the on-line database INFOSTAT.

Not applicable.

Not applicable.

•  Eurostat Methodology papers on of short-term business statistics;
•  Methodology 'Construction Production Indices';

Regulation (EC) № 1165/98 and amending Regulation (EC) № 1158/2005 Short-term statistics obligate the European Commission (Eurostat) regularly (every three years) to report in the Parliament of Europe applicability of short-term data quality and revisions of the data.

Quality report of Eurostat from 2008 Principal European Economic Indicators (PEEI in focus), containing information on the calculation of Indices Production Construction in European countries.

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 provide comparable data of good quality.

The quality of the short-term indicators is measured by each Member State in accordance with the general criteria. Calculation of the variables is carried out in accordance with EU Regulations on Short-term business statistics.

Eurostat, the state governing bodies, associations, businesses, media and others users.

Internal users - Department 'Macroeconomic statistics'.

No information.

The necessary statistical data are provided on the required level of detail, accordance by the relevant STS Regulations.

The general population includes about 23 000 enterprises, of which is formed survey population of more than 6 000 construction enterprises, with more than 4 persons employed. Monthly sample includes about 2 400 enterprises, which formed about 75% from the turnover of construction enterprises.

The sample method used is Stratified Random Sample. Criterion for stratification of the enterprises is 'number of persons employed'. First enterprises are stratified by groups (2-nd digit level of NACE.BG 2008) and then in each group they are stratified by number of persons employed. Enterprises with 30 or more persons employed are surveyed exhaustively. The enterprises with employed from 5 to 14 and from 15 to 29 employed are randomly sampled.

Is ensured a maximum accuracy and reliability of the data from the enterprises included in the monthly sample in section Construction.

Common errors are errors in the measurement data, the respondent misunderstanding what information is required or incomplete performance.

Most measurement errors are detected and corrected by arithmetic and logical controls embedded in Information System "Business Cycles" (On-line information system for collection, verification and processing of data from short-term business statistics). The system performs mandatory and planned control and warning in case there are errors, it displays a warning dialog inconsistencies found. The system does not allow the completion of the report until all outstanding correct mandatory controls.

In the sample of construction firms use the method of 'Stratified random sampling'. To ensure the accuracy of the sample is calculated coefficients of variation and the standard errors are within acceptable limits.

Using programs SPSS, Excel and thorough analysis of the data did not allow the emergence of problems such as excessive coverage, inadequate coverage and repeated entries. For non-response methods are used to update the sample - like editing and imputation data.

Actions for non-responders include: informing and sending reminders, when no-responding company may follows a phone call and / or direct contact to collect the data. The responding rate is average approximately 93%.

The indices of construction production are published 37 - 40 days after the reference month.

All data rows, tables, and press releases are prepared and submitted for publication, accordance STS Regulations and within the deadlines specified in the calendar for publication of data. NSI sent data to Eurostat on the day of national publication.

Construction Production Indices are representative for the whole country and have no representation by regions. The implementation of the EU requirements and national methodology for calculating the Indices of Production in Construction ensures data consistency between Bulgaria and other European countries.

Time series published from 2015.

Data from the monthly statistical survey about hours worked, which is used to calculate the indices of production in construction, are checked with other variable - data for sales (monthly and quarterly) from construction enterprises.

Comparisons are made with the final figures for construction production from the Annual Business Statistics.

The online information system for data collection, data editing and data processing "Business Cycles" reduces the time needed for collecting data from enterprises and ensures more efficient data processing.

Construction Production Indices usually suffered two revisions. Each month data for the reference month are published as a preliminary and data for the previous month as a final. At the beginning of the year, the indices for the previous year are reconciled on the basis of exhaustive annual data from Annual Business Statistics.

Minor changes are made at the time when the revision is introduced and they are marked in footnotes in the relevant published tables.

The revised data are published on the NSI and transmitted to Eurostat.

Information for calculating the indices of construction production - total and separately for building construction, civil engineering and specialized construction activities provides from 'Questionnaire about hours worked from directly employed in construction enterprises', included in the monthly report 'Main short-term indicators'.

Every month.

For the convenience of respondents and getting better and timely information is created on-line information system "Business Cycles". The system controls are set to ensure the accuracy of the information. Possibility remains that the respondent submits monthly report and a paper in the relevant regional statistical office. Experts from RSOs phone calls to provide timely information or clarification of the data.

Validation data starts from the filling of 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 arithmetic and logical controls. 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.

Construction Production Indices are calculated based on the information of construction businesses total hours worked and separately for building construction, civil engineering and specialized construction activities on paper or on-line via the information system "Business Cycles". After validating the data by the regional statistical offices, then the deadline for entry, by experts in the NSI, the data from construction enterprises in the sample are extrapolated and calculated indices of construction production on the national level.

In accordance with Regulations concerning STS, the Construction Production Indices are to be seasonally and working day adjusted. The software used for seasonally and working day adjustment is JDemetra +. The method used is TRAMO-SEATS.

The purpose of working day adjustment is to check and eliminate the significance of the calendar effects as the results from the difference in the number of working days and holidays in the national calendar.

The purpose of seasonal adjustment is to remove ordinary seasonal variation. The series of data are checked for outliers of different types and typical calendar effects on the dynamics of a given indicator. Usually seasonal fluctuations are those changes that are repeated seasonally each year.

Time series the indices of building construction, civil engineering and specialized construction activities are seasonal and working day adjusted, and time series of the indices of construction - total obtained by applying the indirect method.

Revisions of seasonally and working day adjusted data are published in accordance with accepted revision policy and release calendar for the unadjusted data.