National Statistical Institute
|Contact organisation unit|
Non-financial National and Regional Accounts
|Contact person function|
Head of department
|Contact mail address|
2 P. Volov Str., Sofia 1038
|Contact email address|
|Contact phone number|
+359 2 9857 623
|Contact fax number|
Seasonally adjusted data are data that are removed periodically recurring within a one period component of the time series - seasonal and calendar variations. Seasonally adjusted data show highlights the behavior of the studied fluctuations (changes in the direction of development and changes related to the business cycle).
Classification of Economic Activities (CEA-2008, for international use NACE.BG-2008)
Total of economy.
|Statistical concepts and definitions|
Fluctuations caused by abnormal levels of seasonal factors (e.g., extreme weather conditions or unusual circumstances) are visible in the seasonally adjusted data because they exceed or fall below the average seasonal values. Deviations of an occasional nature and unusual changes for which there is an economic explanation (e.g., effects of changes in economic policy, large procurement, natural disasters, etc.) are not eliminated in the season adjustment, i.e. they are part of the seasonally adjusted data.
Seasonal adjustment also includes the elimination of calendar effects, as far as they result from the difference in the number of weekdays and weekends, and can be quantified.
Seasonally adjusted data are data that are removed periodically repeated within period components of the series - seasonal and calendar variations. So seasonally adjusted data highlights the behavior of the studied variables (changes in the direction of development and changes related to the business cycle).
The seasonally adjusted lines contain random component (noise) having different levels in different series and the amount depends on the economic nature of the study, and applying the method of seasonal adjustment .
Seasonal adjustment of statistical indicators in the NIS is organized according to the "Guide of the European statistical system for seasonal adjustment". The procedure is performed using the software developed by Eurostat product Demeter, where by the algorithm TRAMO / SEATS.
The procedure for obtaining seasonally adjusted data includes correction of the series in terms of calendar effects and abnormal values. Calendar effects are expressed as :
Adjustments for differences in the number of working days are made to obtain seasonally adjusted data, which are independent of the number and structure of days (number of Mondays, Tuesdays etc. / number of weekdays and weekends) in the quarter.
Abnormal values (outliers) are unusual changes in time series of a given indicator. Their manifestation can be in several ways, the most significant are the peak values (abnormal values of individual observations in the order), short-term changes (series of abnormal values to change the level of the indicator for a short period of time), changes in the level (a series of abnormal values ??with constant size and time- effect on the level of the indicator).
Institutional unit under ESA2010 - enterprise, household, public institution.
economic territory of the country
from 1995 (Infostat)
Information sources are not adjusted quarterly data for these indicators.
|Frequency of data collection|
Apply seasonal adjustment of the data using software JDemetra+.
· European Statistics Code of Practice;
· Common framework for quality management in the National Statistical System.
Questionnaire on the implementation of the principles of the European Statistics Code of Practice.
|Data completeness - rate|
|Accuracy and reliability|
|Sampling errors - indicators|
|Over-coverage - rate|
|Common units - proportion|
|Non response error|
|Unit non-response - rate|
|Item non-response - rate|
|Imputation - rate|
|Model assumption error|
|Data revision - policy|
About the methods and revisions of seasonally adjusted data, seasonal adjustment of statistical indicators in the NIS is conducted in a harmonized European methodology described in the "Guide of the European statistical system for seasonal adjustment." The procedure is performed using the software developed by Eurostat product Demetra, whereby applied the algorithm TRAMO / SEATS.
|Data revision - practice|
Of seasonal adjustment are subjected data on GDP components. Applies direct method of seasonal adjustment, in which the aggregates and their components undergo self - smoothing. As a result, there is a non - additivity of the seasonally adjusted data - the aggregates are not equal to the sum of their components. The parameters of the model for seasonal adjustment are determined after the calculation of the final data for a given year (October each year) and in case of a change in the used classification of economic activities. This targeted model is used to revise the seasonally adjusted values for the quarters within the whole time series.
|Data revision - average size|
|Timeliness and punctuality|
|Time lag - first results|
|Time lag - final results|
|Punctuality - delivery and publication|
|Coherence and comparability|
|Comparability - geographical|
|Asymmetry for mirror flows statistics - coefficient|
|Comparability - over time|
|Length of comparable time series|
|Coherence - cross domain|
Additional information on other indicators in national accounts are available in other subject areas related to national accounts.
|Coherence - sub annual and annual statistics|
|Coherence - National Accounts|
|Coherence - internal|
|Accessibility and clarity|
Data are available to all users of the NSI website under the heading Macroeconomic statistics - Gross Domestic Product - Quarterly seasonally adjusted data: http://www.nsi.bg/en/node/12590
|Data tables - consultations|
|Metadata - consultations|
|Documentation on methodology|
Guide to the European Statistical System for seasonal adjustment, European System of Accounts (2010) (Eurostat).
|Metadata completeness – rate|
|Cost and burden|
|Confidentiality - policy|
· 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 du account for technical developments and the requirements of users in a democratic society.
|Confidentiality – data treatment|
GDP by Production Methods, Final Expenditure, Income - basic and detailed data – Total of economy (Quarterly seasonally adjusted data)
Download in SDMX 2.1 file format: GDP - Production Methods, Final Expenditure, by Income - basic and detailed data - national level - GDP - seasonally adjusted data
Metadata Structure Definition in SDMX 2.1: ESQRS_MSD+BNSI+2.0+SDMX.2.1.xml
Download in SDMX 2.0 file format: GDP - Production Methods, Final Expenditure, by Income - basic and detailed data - national level - GDP - seasonally adjusted data
Metadata Structure Definition in SDMX 2.0: ESQRS_MSD+BNSI+2.0+SDMX.2.0.xml