Harmonised index of consumer prices (HICP) (prc_hicp)

National Reference Metadata in Euro SDMX Metadata Structure (ESMS)

Compiling agency: National Statistical Institute of Bulgaria.

Time Dimension: 2017-A0

Data Provider: BG1

Data Flow: HICP_ESMS_A

Eurostat metadata
Reference metadata
1. Contact
2. Metadata update
3. Statistical presentation
4. Unit of measure
5. Reference Period
6. Institutional Mandate
7. Confidentiality
8. Release policy
9. Frequency of dissemination
10. Accessibility and clarity
11. Quality management
12. Relevance
13. Accuracy
14. Timeliness and punctuality
15. Coherence and comparability
16. Cost and Burden
17. Data revision
18. Statistical processing
19. Comment
Related Metadata
Annexes (including footnotes)

For any question on data and metadata, please contact: EUROPEAN STATISTICAL DATA SUPPORT


1. Contact Top
1.1. Contact organisation

National Statistical Institute of Bulgaria.

1.2. Contact organisation unit

Consumer Prices, Housing prices and PPP Department.

1.5. Contact mail address

2, P. Volov Str.
1038 Sofia, Bulgaria

2. Metadata update Top
2.1. Metadata last certified 15/02/2017
2.2. Metadata last posted 15/02/2017
2.3. Metadata last update 15/02/2017

3. Statistical presentation Top
3.1. Data description

Harmonised indices of consumer prices (HICPs) give comparable measures of inflation for the countries and country groups they are produced. They are economic indicators that measure the change over time of the prices of consumer goods and services acquired by households. In other words they are a set of consumer price indices (CPIs) calculated according to a harmonised approach and a single set of definitions for EU member states.

3.2. Classification system

COICOP/HICP (Classification of Individual Consumption by Purpose adapted to the needs of Harmonised Indices of Consumer Prices).

3.3. Coverage - sector

HICPs cover the whole household sector, more precisely the goods and services consumed by households.

3.4. Statistical concepts and definitions

The published is as follows:

1. Monthly data:

  • Indices (HICP 2015=100);
  • Monthly inflation rates (previous month=100);
  • Inflation rates since the beginning of the year (December of the previous year=100);
  • Annual inflation rates (corresponding month of the previous year=100);
  • Annual average rates of change (previous 12 months=100).

2. Annual data:

  • Annual rates of change and annual average rates of change;
  • Weights by COICOP divisions.
3.5. Statistical unit

Each published index or rate of change refers to the 'final monetary consumption expenditure' of all households on the territory of the country.

3.6. Statistical population

The target statistical universe is the 'household final monetary consumption expenditure' (HFMCE) within the economic territories of the countries compiling the HICP. The household sector to which the definition refers includes all individuals or groups of individuals irrespective of, in particular, the type of area in which they live, their position in the income distribution and their nationality or residence status. These definitions follow the national accounts concepts in the European System of Accounts (ESA).

HICPs comprise all purchases by households within the territory of a country; those by both resident and non-resident households (i.e. 'domestic concept'). HICPs cover the prices paid for goods and services in monetary transactions. The prices measured are those actually faced by consumers. The HICPs exclude interest and credit charges, regarding them as financing costs rather than consumption expenditure.

3.7. Reference area

The district centers of Bulgaria are covered in the sample of localities where the prices for the HICP are collected. At this stage, non-probability sampling (cut-off) methods are applied. The localities are sampled in proportion to their population and volume of retail sales. Price collection is not carried out in villages or rural areas.
In 2017 the HICP includes 27 district centres (NUTS III) in its sampling framework. Over 50% of the population of the country live there and over 65% of sales are made there.
Furthermore, the sample is stratified between the district centres. The main principle is to have different numbers of price observations from each district centre, depending on its population. The district centres are stratified into three groups: (1) the capital, (2) 'big' and (3) 'small' centres.

3.8. Coverage - Time

Time periods covered by dataset:

Since January 1997 – monthly indices;

Since January 1998 – annual indices;

Since January 1998 – indices since the beginning of the year;

Since January 1999 – annual average indices.

3.9. Base period

The index reference period is 2015 = 100.

4. Unit of measure Top

Following units are used:

  • Index (actually unitless, i.e. it is the ratio of the price of the basket in a given year to the price in the base year multiplied by 100. However, the HICP can be thought of as the amount the average consumer would have to spend in a given year to buy the same basic goods and services that one would have to pay 100 monetary units for in the base period);
  • Percentage change on the previous month (rates);
  • Percentage change on the same period of the previous year (rates);
  • Percentage change on the December of the previous year (rates);
  • Percentage change of the 12 months of current year compared to corresponding period of the previous year (rates);
  • Percentage share of the total (weights).

5. Reference Period Top


6. Institutional Mandate Top
6.1. Institutional Mandate - legal acts and other agreements

Harmonisd Indices of Consumer Prices (HICPs) are harmonised inflation figures required under the Treaty on the Functioning of the European Union. New Framework Regulation - Regulation (EU) 2016/792 of the European Parliament and of the Council of 11 May 2016 on harmonised indices of consumer prices and the house price index, and repealing Council Regulation (EC) No 2494/95 (ОJ L 135, 24.05.2016 ,p.11) sets the legal basis for establishing a harmonised methodology for the compilation of the HICPs.

Under this Regulation, the Commission has brought forward detailed Regulations establishing the specific rules governing the production of harmonised indices. To date, 18 specific regulations governing issues as quality of weights, transmission and dissemination of sub-indices, coverage of goods and services, geographical and population coverage, minimum standards for the treatment of tariffs, insurance, health, education and social protection services, timing of entering prices, treatment of price reductions, treatment of service charges, revisions policy, new index reference period, temporal coverage of price collection and sampling, replacement and quality adjustment procedures, and seasonal items have been adopted. A recommendation on the treatment of health care has also been published.

All relevant regulations as well as further methodological details can be found in the HICP section on Eurostat's website under Methodology => Legislation.

6.2. Institutional Mandate - data sharing


7. Confidentiality Top
7.1. Confidentiality - policy

Regulation (EC) No 223/2009 of the European Parliament and of the Council, of 11 March 2009, on the transmission of data subject to statistical confidentiality to the Statistical Office of the European Communities;

Law on Statistics

7.2. Confidentiality - data treatment

Data are treated in respect of national legislation: Individual data are not published in accordance with article 25 of the Law on Statistics. The publishing of individual data can be performed only in accordance with article 26 of the same law.

8. Release policy Top
8.1. Release calendar

Data on HICP for Bulgaria are released according to Calendar presenting the results of the statistical surveys carried out by the National Statistical Institute in 2017. Release calendar is  publicly accessible on NSI's website: http://www.nsi.bg/en/content/79/basic-page/release-calendar

8.2. Release calendar access

Eurostat's website

NSI’s website:  http://www.nsi.bg/en/content/79/basic-page/release-calendar

8.3. Release policy - user access

On the date of release the press release is sent to the President of the Republic of Bulgaria, the parliament, the government and the media simultaneously. All users have access to the data through the website of NSI and the User Services Division in NSI at the same time.

9. Frequency of dissemination Top

Harmonised indices of consumer prices are disseminated monthly.

10. Accessibility and clarity Top
10.1. Dissemination format - News release

The HICP data is regularly published together with CPI data to a strict, pre-announced time table - in general from 12 to 15 days after the month in a question.
The HICP data which is released each month covers the price indices (2015=100), monthly indices and rates of change, annual indices and indices for the current month compared to December of the previous year.

10.2. Dissemination format - Publications

HICP table data and press release are available on NSI’s website, theme Inflation and Consumer Price Indices

HICP data are also published in the following NSI publications in printed and/or electronic format:

  • Statistical Yearbook (Bulgarian/English);
  • Key Indicators for Bulgaria (Bulgarian/English);
  • Statistical Reference Book (Bulgarian/English);
  • Brochure Bulgaria (Bulgarian/English);
  • Statistical Panorama (in Bulgarian and summary in English).
10.3. Dissemination format - online database

HICP database.

10.4. Dissemination format - microdata access


10.5. Dissemination format - other


10.6. Documentation on methodology

The HICP methodology is available on the NSI's website, theme Inflation and Consumer Price Indices

10.7. Quality management - documentation

See Eurostat's Compliance Monitoring Report of 2007 and 2015.

11. Quality management Top
11.1. Quality assurance

In the context of compliance monitoring and quality assurance, Eurostat reviewed the HICP for Bulgaria in autumn 2007 and in 2013 (published 2015). The statistical practices used to compile the HICP for Bulgaria have been reviewed against HICP methodology and other guidelines and good practices in the field of consumer price indices. The recommendations have been followed by NSI and have been implemented in practice in order to assure accuracy, reliability and comparability of HICP.

In 2013 NSI elaborated an inventory of HICP sources and methods which is one of the main elements of the new strategy for monitoring the compliance of HICP produced by countries with the acquisitions of HICP reglaments. The inventory provides detailed description of the current practice in NSI and is the base for assessment to what extend the national practice is relevant to the legal requirements as well as the base for Compliance monitoring conducted by Eurostat.

11.2. Quality management - assessment

The representativity of the HICP, in terms of accuracy and reliability, is generally adequate. HICP is considered to be sufficiently accurate for all practical purposes it is put into. See Eurostat's Eurostat's Compliance Monitoring Report of 2007 and 2015.

12. Relevance Top
12.1. Relevance - User Needs

The main users are:

International institutions: Eurostat, ECB, IMF, UN ECE, etc.

National users: National Assembly of The Republic of Bulgaria, The Government, BNB, Ministries, National and State Agencies, private agencies for analyzes and prognosis, enterprises, students, National Accounts and other divisions in Bulgarian NSI, media and public.

12.2. Relevance - User Satisfaction

NSI conducts a regular statistical survey "Users' satisfaction" which covers all statistical domains. It aims to assess user satisfaction in NSI data provision and to outline the recommendations for future development of statistical system according to the needs of the users.

12.3. Completeness

No missing data. Bulgaria produces and delivers the full set of HICP indices and weights.

13. Accuracy Top
13.1. Accuracy - overall

Statistical data are with good accuracy. The accuracy of HICP is assured by strictly following Eurostat's methodological recommendations and regulations. The type of survey and the price collection methods ensure sufficient coverage and timeliness.

13.2. Sampling error

The HICP estimates are subject to sampling errors because they are based on a sample of consumer prices and household expenditures, which are not the complete universe of all prices/expenditures.

The common use of purposive sample makes it difficult to assess the sample error. Therefore and due to the complexity of price index structures NSI does not produce estimates on sampling errors.
Nevertheless the NSI aims to avoid possible bias due to sample misrepresentation by using a sample of consumer prices that is as large as possible by the given resource constraints. The NSI tries to optimise the allocation of resources by indicating the number of prices that should be observed in each geographic area and each item category, in order to minimize the variance of the all-items index.

13.3. Non-sampling error

For the HICP non-sampling errors are not quantified. The NSI tries to reduce non-sampling errors through continuous methodological improvements and survey process improvements, which can help us to avoid coding and typing errors.

14. Timeliness and punctuality Top
14.1. Timeliness

On the 1st working day after the 11th calendar day of the month following the reference month, i.e. HICP data are published 12-15 days after the month in question.

14.2. Punctuality

Data are always delivered and published on the pre-announced release dates.

15. Coherence and comparability Top
15.1. Comparability - geographical

Since Bulgarian HICP is based on the harmonised definitions and classification stipulated in a series of legal acts it should be considered comparable to the HICPs of other EU countries.
The work carried out for the harmonisation of quality adjustment and sampling methods is expected to further improve the comparability of the Bulgarian HICP.
In construction of the Bulgarian HICP the national stratification is used and no regional indices are produced.

15.2. Comparability - over time

HICP data are fully comparable over time. There have been several improvements in methodology since HICP was introduced with the aim of improving reliability and comparability of the HICP. These changes may have introduced breaks in time series. However back calculations under the newer standards were performed when appropriate basic data was available and historical series were revised.

15.3. Coherence - cross domain

Differences between the HICP and national CPI
The HICP calculated differs from the national CPI. The main reasons for the difference between the two indices are:

  • The different coverage of the HICP and CPI in respect of the treatment of the consumption by non-residents: consumption by non-residents on the territory of the country is covered by the HICP, but not included in the CPI.
  • The different sources of data and, therefore, different reference period covered by the HICP and CPI weights. The main sources for the HICP weights are the NA data (the HICP in year t is calculated from the weights for year t-2), while the main data source for the CPI weights is the household budget survey (the CPI in year t is calculated from the weights for year t-1).
15.4. Coherence - internal

HICP is internal coherent. Higher level aggregations are derived from detailed indices according to well-defined procedures.

16. Cost and Burden Top

Not available.

17. Data revision Top
17.1. Data revision - policy

HICP series, including back data, are revisable under the terms set in Commission Regulation (EC) No 1921/2001 of 28 September 2001. The published HICP data may be revised for mistakes, new or improved information, and changes in the system of harmonised rules.

17.2. Data revision - practice

In general, monthly indices are not subject to revision. They are final when first released.

18. Statistical processing Top
18.1. Source data

Sample size (reference year 2017):

No of price observations per month: 37 587

01 Food and non-alcoholic beverages 13 403

02 Alcoholic beverages, tobacco 1 590

03 Clothing and footwear 6 180

04 Housing, water, electricity, gas and other fuels 1 163

05 Furnishings, household equipment and routine household maintenance 3 599

06 Health 3 097

07 Transport 1 377

08 Communication 151

09 Recreation and culture 1 755

10 Education 88

11 Restaurants and hotels 2 711

12 Miscellaneous goods and services 2 473

Number of representative products
(goods and services) (reference year 2017)

All items: 722

01 Food and non-alcoholic beverages 154

02 Alcoholic beverages, tobacco 25

03 Clothing and footwear 114

04 Housing, water, electricity, gas and other fuels 29

05 Furnishings, household equipment and routine maintenance of the house 64

06 Health 58

07 Transport 47

08 Communication 58

09 Recreation and culture 62

10 Education 6

11 Restaurants and hotels 54

12 Miscellaneous goods and services 51

Number of observation points (reference year 2017): 6 466

18.2. Frequency of data collection

Timing of price observation
Prices of most goods and services are collected each month between the 1st and 28th of the month (prices are not collected during weekends and public holidays). The exceptions to this rule are the prices of some specific services which are registered each week (for example, Package holidays), or at the beginning or at the end of the month (for example, Kindergarten), or twice in a year (for example, University fees).
Most of the prices are observed regionally by price collectors – qualified specialists employed by the regional statistical offices (RSOs): locally collected prices account for 77% of the total HICP weight. The prices of electricity, cars, mobile phones, personal computers, tablets, pre- recorded recording media, electronic games, insurance, books, newspapers, magazines and periodicals, package holidays, hotels in holiday centres, banking services, administrative fees, legal services and accountancy and some health, transport and telecommunication services are collected centrally.

18.3. Data collection

Outlet selection
The prices are collected at selected observation points (outlets) – a sample of stores, shops, restaurants, cafes, etc. in the sample of localities. The sampled outlets are chosen using non-probability sampling methods: 'purposive' or 'judgmental' sampling. They are selected at regional level by price collectors in the regional statistical offices.
The number and structure of the observation points ensure that the optimum number of prices is collected, enough to represent national prices for any group of goods and services observed. The number of observation points is determined in proportion to the population in the selected district centres and to the volume of retail sales in the relevant outlets. The sample includes outlets which:

  • have a large volume of retail sales;
  • supply a variety of goods representative of the relevant elementary aggregate groups.

The main types of trade are covered, including supermarkets, hypermarkets, general and specialised stores and market stalls. Mail order and Internet shopping are not included in the index (until now they have not been significant). Prices for PCs, mobile phones, mobile and fixed phone services and package holidays are collected from the Internet sites of the relevant suppliers.

Methods of product selection and specification
The prices of a specially selected representative sample of goods and services ('consumer basket') are collected. The products are selected and specified jointly by staff in central office and by price collectors in the regional statistical offices.
The procedures for specifying the representative goods and services can be described as follows:

  • Definition of an initial product sampling framework using HBS results;
  • Use of alternative data sources to define the exact characteristics of the products sampled (administrative data, private databases, etc.), in addition to HBS data, where possible;
  • Use of price collectors’ field experience if the data from the HBS and other sources are not enough to define and specify the products sampled;
  • Extraction of the sample using purposive sampling methods.

The specifications for individual goods/services are more or less detailed, indicating size, unit, materials, model, brand characteristics, etc. How tight or loose the specifications will be depends on the nature of the product. If a product has many characteristics which could affect its price, the specification is more detailed.
The specific variety of each good/service (reference product-offer) whose price will be collected in the outlet sampled is selected by price collectors. They are instructed to pick the 'typical' product variety:

  • Which is the top selling variety in the outlet sampled; and
  • Which meets the specification of the product as closely as possible.

At the end of each year, during the annual revision of the CPI/HICP, a series of instructions for price collectors are sent to the RSOs. They cover the procedures for selecting the particular product in outlets. The issue is also discussed at regular seminars/workshops with price collectors.

18.4. Data validation

Data quality checks and validation are distributed between the central office and regional statistical offices, but most of the data are edited at national level by the Consumer Prices Statistics and PPP Division in the NSI.
The data validation process at regional offices can be divided into two stages. The first one takes place during the entering of the collected prices into the computer system, the second stage includes checking and validating by specialists in regional statistical offices and if necessary, prices are cross-checked in outlets.
The data are validated at the central office after the first index is calculated. The prices are checked and validated by three people in the CPI Division. Data quality checks can be subdivided into validation of: changes in the relevant index (extreme and unusual price levels/changes); missing prices; replacement of outlets; changes in product specifications; changes in fresh product prices, etc.
In this validation process there is no automatic rejection of observed prices. Each problematic price is considered individually and any necessary modifications are made only on the basis of relevant information.

18.5. Data compilation

The HICP weights are constructed in accordance with the requirements of Commission Regulation (EU) No 1114/2010 and Council Regulation (EC) No 1688/98. The HICP weights reflect the structure of the HFMCE (domestic concept).
National accounts are the main source of data for construction of the HICP weights at the highest levels of aggregation. HICP in year t is calculated with weights of year t-2. In constructing the HICP weights, the NA data are adapted as follows:

  • Household final consumption expenditure (HFCE — domestic concept), as shown by NA;
  • Own final consumption (to the extent that it forms part of HFCE and does not involve monetary transactions), mainly imputed rentals (COICOP 04.2.0);
  • Expenditure on the following COICOP classes are excluded:

a) Narcotics (COICOP 02.3.0);

b) Games of chance (COICOP 09.4.3);

c) Prostitution (COICOP 12.2.0);

d) Service charge for life insurance (COICOP 12.5.1);

e) Administrative charges of private pension funds and the like (COICOP 12.6.2).

Data from the household budget survey (HBS) are used for construction of the weights at the lower levels of aggregation, where no information is available from the NA.
Additional data sources are used for construction of detailed weights for for electricity, heat energy, telecommunications, tobacco, clothing and footwear, medicines, fuels, automobiles, actual rentals for housing, insurances, accommodation services, books, newspapers etc. At the lowest level of aggregation 362 elementary aggregates are defined.
The item weights are expressed as a share of total expenditure on all goods and services falling within the scope of the index.
NA data for 2015 in combination with HBS data for 2016 are used as weights for calculating the HICP for 2017. Weights are price-updated to December 2016 to ensure a common base period for the index.
Weights are reviewed and updated annually, based on the NA and HBS results and other data sources.

Computation of lowest-level indices
For computation of price indices for elementary aggregates the ratio of the geometric mean prices is used.

Treatment of missing items and replacements
Temporarily missing prices are imputed in the first and second months. The missing prices are estimated using the method of matching samples and applying the short-term approach: they are imputed using the short-term price relative. If the price is still missing in the third month, the price collector must select a replacement.
When replacing an old product by a new alternative product, price collectors are instructed to:

  • Choose another product with the most similar quality and which accounts for a substantial share of sales value at the outlet; and
  • Ask for the price of the new replacement product in the previous month.

When replacing an outlet, price collectors are told to choose a new one:

  • As close as possible to the old outlet;
  • Of the same type;
  • As similar as possible to the old outlet in terms of sales value.

Introduction of newly significant goods and services
The procedure for identifying newly significant goods and services is based on:

  • Analyses of HBS data on the structure of household expenditure;
  • Information from price collectors;
  • Research and consultations with suppliers;
  • Nomenclature of goods and services, included in the PPP surveys;
  • Eurostat's list of the newly significant goods and services introduced to the member states.

Newly significant goods and services are introduced at the end of each year (in December) during the annual revisions of the consumer basket.

Treatment of price reductions
Seasonal sales, other sale prices and price reductions (e.g. special offers, discounts, etc.) are included in the index when they are available to all potential consumers with no special conditions attached.

Treatment of seasonal items
The seasonal products are treated according to the requirements of the Commission Regulation (EC) N 330/2009. The fixed-weight approach is used for determining the weights for seasonal items, i.e. during the whole year the indices of seasonal products are calculated with fixed weights.

The prices of the missing fruits and vegetables during the out-of-season are estimated using the method of 'all-seasonal estimation':

  • In the first month of out-of season period, the estimated price is equal to the average price of the previous in-season period;
  • From the second month of out-of season period, the estimated price is equal to the price of the previous month, adjusted by the price change of all available products.

The prices of the missing clothing and footwear during the out-of-season are estimated using the method of 'counter-seasonal estimation':

  • In the first month of out-of season period, the estimated price is equal to the average price of the previous in-season period;
  • From the second month of out-of season period, the estimated price is equal to the price of the previous month, adjusted by the price change of all seasonal products that are in-season.
18.6. Adjustment

Adjustment for quality differences
When the HICP is calculated, it is important that the products are priced without any change in quality, because only 'pure' price changes, not any due to changes in the quality of the products observed, should be reflected.
The most commonly used methods of dealing with changes in product quality are:

  • Annual overlap: For many products new samples are selected each year during the annual revision of the consumer basket. December is taken as the link month when prices are collected for both the old and new samples. Quality differences between these two samples are then eliminated by the 'annual overlap' method.
  • Direct comparison: Price collectors are instructed to measure the price for the same variety throughout the year. If the variety disappears permanently from the market, they should choose another with the most similar quality. In these cases, direct comparison is applied because the difference in quality between the old and new varieties is minor.
  • Implicit quality adjustment methods: In some cases the second approach is not applicable, because the quality difference between the old and new products is 'significant'. Implicit quality adjustment methods are then applied. Classic overlap is used when the prices of both products are available over the same time period and bridged overlap (or class-mean imputation) when prices are not available. Option costs method is applied mainly for household appliances, cars, audio-visual, photographic and information processing equipment.

Quality adjustment procedures are performed centrally by the staff at central office. At regional level, price collectors make no quality adjustments. They are just instructed to report to the central office all cases of considerable quality changes due to replacement of products.

19. Comment Top


Related metadata Top

Annexes Top