Eurostat, the statistical office of the European Union

Unit C2 - National Accounts - production

2920 Luxembourg LUXEMBOURG

National accounts are a coherent and consistent set of macroeconomic indicators, which provide an overall picture of the economic situation and are widely used for economic analysis and forecasting, policy design and policy making. Eurostat publishes annual and quarterly national accounts, annual and quarterly sector accounts as well as supply, use and input-output tables, which are each presented with associated metadata. Even though consistency checks are a major aspect of data validation, temporary (usually limited) inconsistencies between datasets may occur, mainly due to vintage effects.

Annual national accounts are compiled in accordance with the European System of Accounts - ESA 2010 as defined in Annex B of the Council Regulation (EU) No 549/2013 of the European Parliament and of the Council of 21 May 2013.

The previous European System of Accounts, ESA95, was reviewed to bring national accounts in the European Union, in line with new economic environment, advances in methodological research and needs of users and the updated national accounts framework at the international level, the SNA 2008.

The revisions are reflected in an updated Regulation of the European Parliament and of the Council on the European system of national and regional accounts in the European Union of 2010 (ESA 2010). The associated transmission programme is also updated and data transmissions in accordance with ESA 2010 are compulsory from September 2014 onwards.

Further information (including actual communications) is presented on the Eurostat website.

The domain consists of the following collections:

1. Main GDP aggregates: main components from the output, expenditure and income side, expenditure breakdowns by durability and exports and imports by origin.

2. Key auxiliary indicators such as population and employment data, which are used to derive main GDP aggregates per capita as well as productivity and unit labour cost indicators.

3. Breakdowns of GDP aggregates and employment data by main industries and asset classes.

4. Breakdowns of main GDP aggregates (by industry and consumption purpose)

5. Breakdowns of non-financial assets by type, industry and sector

Geographical entities covered are the European Union, the euro area, EU Member States, Candidate Countries, EFTA countries, US, Japan and possibly other countries on an ad-hoc basis.

Data sources: National Statistical Institutes

The standard followed is the European System of National and Regional Accounts (ESA 2010).  This is the newest internationally compatible EU accounting framework for a systematic and detailed description of an economy. The ESA 2010 was published in the Official Journal on 26 June 2013. From September 2014 the data transmission from Member States to Eurostat follows ESA 2010 rules.

Annual national accounts comprise the main aggregates on annual national accounts, including: GDP and its components, employment, final consumption aggregates, exports and imports.

Breakdowns exist for variables by economic activity, type of non-financial asset and final consumption by purpose. 

Economic activity

ESA2010 uses aggregation levels of the NACE Rev.2 classification to define industry breakdowns (NACE stands for Nomenclature générale des Activités économiques dans les Communautés Européennes). NACE Rev.2 is a classification of economic activities widely used in statistics and in other domains. Requirements for the transmission of NACE Rev.2 series have been specified in the Commission Regulation (EC) No 715/2010 of 10 August 2010

Asset types

The new transmission programme of national accounts data (annex B of Regulation (EC) No 1392/2007) foresees the following asset types (AN_F6) for quarterly data on gross fixed capital formation:

AN.111 dwellings

AN.112 other buildings and structures

AN.113 + AN.114 machinery and equipment + weapon systems

   - AN.1131 transport equipment

   - AN.1132 ICT equipment*

   - AN.1139 + AN.114 other machinery and equipment + weapon systems*

   - AN.115 cultivated biological resources

   - AN.117 intellectual property products

(*) on voluntary basis

Consumption purpose

Household consumption expenditure can be classified by consumption purpose according to the COICOP classification (Classification Of Individual COnsumption by Purpose, see also Commission Regulation 113/2002 of 23 January 2002). COICOP categories at two-digit level are as follows:

01 - Food and non-alcoholic beverages

02 - Alcoholic beverages, tobacco and narcotics

03 - Clothing and footwear

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

05 - Furnishings, household equipment and routine household maintenance

06 - Health

07 - Transport

08 - Communication

09 - Recreation and culture

10 - Education

11 - Restaurants and hotels

12 - Miscellaneous goods and services*

(*) Coicop groups 12.2 'Prostitution' and 12.7 'Other services, not elsewhere classified' are to be provided as an aggregate.

For a complete review of classifications used, please refer either to:

- ESA 2010 Chapter 23 'Classifications',

- 'The European System of Accounts 2010 Transmission Programme' Annex B of the Council Regulation (EU) No549/2013 of the European Parliament and of the Council of 21 May 2013 (cf. also Article 3 of this regulation);

- Eurostat's RAMON classification database

- United Nations classification registry.

Annual national accounts refer to the whole economy, but breakdowns by sectors are provided by the annual sector accounts.

This domain encompasses the main aggregates on national accounts. Its main variables are: GDP and its components, employment, final consumption aggregates, gross capital formation aggregates, income, exports and imports. The above variables are calculated on an annual basis but the majority of them are also calculated on a quarterly basis. Breakdowns exist for certain variables by economic activity (NACE Rev.2), by non-financial asset (AN_F6) and final consumption purpose (COICOP).

The following are brief definitions of concepts and variables from the European System of Accounts 2010 (ESA 2010). In general, the ESA 2010 which was published in the Official Journal as Annex A of Regulation (EU) No 549/2013, may be referred to for more detailed explanations on methodology.

The main aggregates domain excludes estimates in the allocation of primary income account and Gross National Income, which were previously included as part of the national accounts main aggregates.  These estimates have now been reclassified to the national accounts sector accounts dataset.

In summary the key concepts captured by the national accounts main aggregates datasets cover the following definitions:

GDP - Gross domestic product

GDP at market prices is the final result of the production activity of resident producer units  It is defined in three ways:

a. GDP Output approach

From the production point of view GDP can be measured as the sum of the following components:

GDP = Total gross value added (B.1G) + Taxes less subsidies on products (D.21 less D.31)

where

Gross Value Added (GVA)= Output (P.1) less Intermediate consumption (P.2)

b. GDP Expenditure approach

From the expenditure side, GDP can be measured as follows:

GDP =

Household and non-profit institutions serving households final expenditure  (P.3 in S.14+S.15)

+ government final consumption expenditure (P.3 in S.13)

+ gross fixed capital formation (P.51)

+ changes in inventories (P.52)

+ acquisition less disposal of valuables (P.53)

+ exports (P.6)

- imports (P.7)

c. GDP Income approach

GDP =

Compensation of employees (D.1)

+ gross operating surplus and mixed income (B.2g and B.3g)

+ taxes less subsidies on production and imports (D.2 and D.3)

Note: GDP income components and other income measures are only available at current prices, because purely monetary flows cannot be decomposed into a price and a volume component. They may, however, be converted to "real terms" by applying an appropriate deflator. The central variables given are related with each other according to the following equations:

Population and employment. While not strictly national accounts aggregates, these variables are widely used in a national accounts context. Employment and its components are important economic indicators in their own right, and they serve in the construction of derived indicators, turning monetary aggregates from absolute into relative indicators and thus allowing the comparison of economies of very different size.

Population consists of all persons, nationals or foreigners, who are permanently settled in the economic territory of the country, even if they are temporarily absent from it, on a given date. A person staying or intending to stay at least one year is considered to be settled on the territory. By convention, the total population excludes foreign students and members of foreign armed forces stationed in a country.

Employment covers all persons engaged in some productive activity (within the production boundary of the national accounts). Employed persons are either employees (working by agreement for another resident unit and receiving remuneration) or self-employed (owners of unincorporated enterprises).

For information explaining the units of measure see section 4 (Unit of Measure) below.

National accounts aim to capture economic activity within the domestic territory. They combine data from a host of base statistics, and thus they have no common sampling reference frame. The elementary building blocks of ESA 2010 statistics are statistical units and their groupings.  ESA 2010, defines two types of units, institutional units and local kind-of-activity units (ESA 2010, 1.54).

National accounts combine data from many source statistics. The concept of statistical population is not applicable in a national accounts context.

Eurostat publishes national accounts data for European Union, euro area, EU Member States, EFTA countries, enlargement countries, the United States, Japan and possibly other countries on an ad-hoc basis.

Eurostat estimates the aggregates for the EU and the euro area.  All other data are produced by the statistical offices of the respective countries. For further information on country data you may also refer to National Statistical Institutes and National Central Banks (links given on the Eurostat web site).

EU Member States and EFTA countries have legal obligations to submit their data to Eurostat as defined in the European System of Accounts ESA 2010 transmission programme of data. These data are the inputs for Eurostat's estimates of EU and the euro area. Since the United States and Japan have no such obligation to transmit data to Eurostat, coverage is usually limited to key aggregates, and delays between national publication and availability on Eurostat's website may be longer. Note that for some countries not covered in the national accounts domain, some central aggregates such as GDP may be available from the general statistics domain of Eurostat's online database.

Time coverage (i.e., length of the historical series) is different for European series and for national series. Coverage is given for EU and euro area aggregates starting from 1995, with some exceptions in the case of the New Member States and derogations. The coverage for national data varies from country to country, partly due to derogations provided for in the transmission and back-projection programme, and can, in some cases, be substantially longer than for the European aggregates.

Forecasts (usually two years ahead) for national and European series based on forecasted growth produced by the Commission's General Directorate Economy and Finance (DG ECFIN) may be retrieved from DG ECFIN's website: http://ec.europa.eu/economy_finance/eu/forecasts/

Not applicable.  The Commission Decision 98/715/EC requires previous year prices and volume estimates to be presented in chain-linked series.  

The national accounts main aggregates data are presented using a range of unit measures including current price, volume and implicit deflator series in one table, as well as specific units for the employment and labour productivity tables. Please note that series are not available for all tables: For instance, figures related to EU average can only be derived after the estimation of the respective aggregate and the presentation focuses on the most relevant units for typical users.

Current price figures are typically expressed in (millions of) national currency and euro. They can be directly observed but include inflation effects. Additional units and ratios for current prices are derived and presented to facilitate comparisons of economic structures across time or countries.

• National currency series (CP_MNAC) (including fixed euro series for euro area Member States) are transmitted by Member states and correspond to nationally published figures. They are suitable for studying the development of a variable in a single country over time.
• Euro series (CP MEUR ) are derived from transmitted national currency series using historic exchange rates. They are suitable for internal comparison and aggregation. When comparing them over time, account must be taken of exchange rate effects.
• For euro area Member States, the national currency series are converted into euros using the irrevocably fixed exchange rate. This "preserves the same growth rates than for the previous national currency series. Both series coincide for years after accession to the euro area but differ for earlier years due to market exchange rate movements.
• Purchasing Power Standards (PPS) (CP_MPPS) are fictive 'currency' units that remove differences in purchasing power, i.e. different price levels between countries. These parities are obtained as a weighted average of relative price ratios in respect to a homogeneous basket of goods and services, both comparable and representative for each country. They are fixed in a way that makes the average purchasing power of one euro in the European Union equal to one PPS. PPS series should be used for cross-country comparisons in a specific year but do not for comparisons over time since they do not constitute time series.
• To facilitate the comparisons between countries, data are expressed in percent of the EU aggregate, e.g. using euro (PC_EU_MEUR_CP) or euro (PC_EU_MEUR_CP)
• Figures are also expressed in relation to total GDP (PC_GDP) or the total aggregate (PC_TOTAL) in case of breakdowns by industry or assets to facilitate comparisons of the relative importance of the aggregates over time or across countries:

Volume figures show the development of aggregates excluding inflation. They are typically derived as previous year prices but presented as chain linked volumes, indices or various growth rates. 

• National accounts volumes for transactions concerning goods and services are estimated in previous year prices (PYP_MNAC or PYP_MEUR) to eliminate the influence of inflation. They are used to derive chain-linked volumes and included in the dissemination for advanced users to allow construction of custom aggregations and derived measures. Since the price base changes every year, the figures do not constitute a homogeneous time series.
• Chain-linked level series obtained by successively applying previous year's price's growth rates to the current price figure of a specific reference year e.g. 2010 (CLV10_MNAC, CLV10_MEUR). 2005 based chain linked volumes (CLV05_MNAC, CLV05_MEUR) are still presented to facilitate comparison with ESA 95 series.
• Chain-linking involves the loss of additivity for all years except the reference year and the directly following year, because these are the only periods expressed in prices of the reference year. For other years, chain-linked components of GDP will not sum to chain-linked GDP, and chain-linked Member States' GDP will not sum to chain-linked EU GDP.
• In addition, chain-linking cannot be performed directly on variables that can take both negative and positive values. Therefore, no chain-linked series are provided for changes in inventories (P.52), acquisition less disposal of valuables (P.53) and the external balance (B.11, B.111 for goods only, B.112 for services only). These components are only available only at current prices and at previous year's prices.
• Index series (CLV_I10) are derived by successively applying previous year's price's growth rates to an index value 100 in the reference year. The volume growth rates are equal with the growth rates in the level series mentioned above. Index series are given only for the reference year 2010 since they can easily be re-referenced (reference year = 100)  to another year.
• Growth rates are derived from the level series mentioned above (they all give the same growth rates irrespectively of the currency denominated since the exchange rate is "fixed" to the one in the reference year). CLV_PCH_PRE represent the percentage change over previous period. In the case of annual data, this is the previous year.
• Contributions to growth are derived for European aggregates since chain-linked volume series do not add up to GDP growth outside the reference year. They reflect the fact that a change in GDP can be attributed to changes in its components, hence showing which component contributed strongly to economic growth and which did not. A component's contribution depends on both its size and its growth. They are calculated as percentage point change over previous period (CON_PPCH_PRE) or the same period in previous year (CON_PPCH_SM). Except for rounding effects, all contributions should sum up to the GDP growth rate.

Implicit deflator series are derived as a ratio of current price to chain-linked volumes series and give indication of underlying price changes.

• The series differ for national currency or euro series and can be expressed as an index (PD10_NAC or PD10_EUR)or growth rates (PD_PCH_PRE_NAC, PD_PCH_SM_NAC, PD_EUR, PD_PCH_PRE_EUR, PD_PCH_SM_EUR).

Population, employment and derived indicators

• Estimates of population, employment and labour productivity data are presented in (thousands of) persons (THS_PER), total hours worked (THS_HW) and jobs (THS_JB). To facilitate the analysis of the indicator over time, series can also be expressed as index figures or growth rates.
• Labour productivity and unit labour costs can be expressed in percent of EU total (PC_EU_PPS, PC_EU_EUR), index (I10) or growth rates (PCH_PRE, PCH_3Y, PCH_5Y, PCH_10Y).

Values of non-financial assets in the balance sheet data are presented in current replacement costs and previous year replacement costs, expressed in euros and units of national currency.

The accounting period is the calendar year, with temporal coverage varying across geographical units.

National accounts are compiled in accordance with the European System of Accounts (ESA 2010) which was published in the Official Journal as Annex A of Regulation (EU) No 549/2013.

The European System of Accounts (ESA 2010) transmission programme is covered in Annex B of the Council Regulation (EU) No 549/2013

Commission Decision 98/715 of 30 November 1998 and Commission Decision 2002/990 of 17 December 2002 on measurement of price and volumes in national accounts.

Data received via the transmission programme are shared with other institutions in accordance with specific agreements, notably with the ECB and the OECD. A Protocol for co-operation between Eurostat and the OECD in the area of National Accounts signed in June 2013 specifies agreed data exchange and data validation arrangements.  Further data sharing between international organisations is currently tested.

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.

If Member States transmit data with a confidentiality flag or an embargo date, these data are not disseminated until the confidentiality flag is removed in a subsequent data transmission or the embargo expired.

Eurostat releases of European annual accounts aggregates are not covered by a pre-announced release calendar, but annual accounts that are also covered by the quarterly accounts are usually updated on the occasion of new quarterly releases (which are released according to a pre-announced calendar that is published on Eurostat's website), and figures for a new year usually become available with the first release of quarterly accounts for the fourth quarter of the reference year.

National data are published by the National Statistical Institutes (NSI) following national dissemination calendars. Please consult NSI's websites to obtain national dissemination calendars (links are given on the Eurostat website). National data become visible on Eurostat's online database usually one to two days after their reception (processing including quality monitoring). 

The release calendar for European quarterly national accounts is published on the website: http://ec.europa.eu/eurostat; see “QNA release calendar” on dedicated section or the annual planning published in the dedicated section: "National accounts (including GDP)" under “See also”.

In line with the Community legal framework and the European Statistics Code of Practice Eurostat disseminates European statistics on Eurostat's website (see item 10 - 'Accessibility and clarity') respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably. The detailed arrangements are governed by the Eurostat protocol on impartial access to Eurostat data for users.

In line with this protocol and on a strictly regulated basis, European estimates of main national accounts aggregates including GDP and employment are sent for information to the European Central Bank (ECB), to the European Commission Directorate General for Economic and Financial Affairs (DG ECFIN) and the Directorate General for Employment, Social Affairs and Equal Opportunities (DG EMPL) (employment only) under embargo the evening before official release of data.

The transmission requirements for each dataset are defined in the European System of Accounts (ESA 2010) transmission programme.

For annual data these are, in principle:

• Main GDP aggregates (nama_10_ma): t+2 months and t+9 months
• Auxiliary indicators (population, GDP per capita and productivity) (nama_10_aux):  t+2 months and t+9 months
• Basic breakdowns of main GDP aggregates and employment (by industry and by assets) (nama_10_bbr)  
• Main GDP aggregates (nama_10_ma) including auxiliary indicators (nama_10_aux) and basic breakdowns:  t+2 months and t+9 months
• Detailed breakdowns of main GDP aggregates (by industry and consumption purpose) (nama_10_dbr): t+9 months
• Breakdowns of non-financial assets by type, industry and sector (nama_10_nfa): t+24 months

There is no specific news release for annual main national accounts aggregates, but the first estimates of EU/EA annual growth are published with the quarterly national accounts flash release and second news releases for the fourth quarter, and annual data are estimated and updated with the subsequent quarterly releases announced on the website “National accounts (including GDP)” under “See also”. 

Statistics Explained; data are also used in various other publications.

Please consult the respective section of Eurostat’s public database. Estimations of annual main European national accounts aggregates are updated in line with the regular quarterly estimates (see 10.1). Member States’ annual data are published shortly after their transmission, with first estimates generally due at t+2 months and t+9 months (for details see ESA 2010 transmission programme).

Please consult NSI's websites to obtain national dissemination calendars.

Not applicable.

Apart from the accompanying press release, there are no official comments from Eurostat at the time of the release of the European aggregates. Comments may or may not be made by the European Commission or European Union Member States.

For information on any comment possibly made by the Commission, please refer to http://europa.eu/rapid/latest-press-releases.htm. For further information on any comments possibly provided by National Statistical Institutes, National Central Banks or National Governments on their own data, please refer to their web sites (Links are given on the Eurostat web site http://ec.europa.eu/eurostat).

European legislation and guidelines are explained in ESA 2010 (see link above under "6.1 Legal acts and other agreements ").

Not available.

Quality is assured by strict application of ESA 2010 concepts and by thorough validation of the data delivered by countries.

ESA 2010 data transmissions are subject to regular quality assessment reviews. Article 4 of Regulation (EU) No 549/2013 (ESA 2010 Regulation) specifies that the data covered by that Regulation is subject to the quality criteria, namely relevance, accuracy, timeliness and punctuality, accessibility and clarity, comparability and coherence, as set out in Article 12(1) of Regulation (EC) No 223/2009 of the European Parliament and of the Council. Member States are to provide the Commission with a report on the quality of the transmitted data on national and regional accounts. The modalities, structure, periodicity and assessment indicators of the quality reports on data transmitted have been specified in a Commission Implementing Regulation 2016/2304 of 19 December 2016. The implementation of the quality reporting and assessment exercise started in 2017 and is carried out annually. As part of the annual exercise, Eurostat assesses the results, prepares and publishes an overall assessment based on the national quality reports and other available information. The Commission also, on a 5 year basis, reports to the European Parliament and the Council on the application of the ESA 2010 Regulation, including the quality of data on national and regional accounts. The first of such reports was published in 2018: REPORT FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL on the application of Regulation (EU) No 549/2013.

Users of annual national accounts data are typically interested in analysing structural changes in the economy from a medium-term perspective.

Annual national accounts data are a key instrument for economic analysis.

Annual national accounts data provide detailed breakdowns on production, consumption, investment and income.

Eurostat publishes Euro area GDP revision triangles with all vintages of quarter-on-quarter growth rates and year-on-year growth rates for the Euro area 12 (EA12) seasonally and working day adjusted volume GDP as published by Eurostat since May 2003 until September 2014. Quality reports on national accounts, including revision analysis are also published by some Member States.

Not applicable.

Not applicable.

Member States are required to transmit their data to Eurostat in compliance with the European System of Accounts ESA 2010 transmission programme, subject to derogations.

Eurostat releases its estimates of European aggregates in line with the pre-announced release schedule (see: dedicated section). Member states' data are revised according to national schedules, and revisions are applied to Eurostat’s online database as soon as they become available to Eurostat.

The comparability is insured by the application of common definitions (European System of Accounts ESA 2010).

By using a common framework, the European System of Accounts  ESA 2012, data can be comparable over time.  Where series cannot be comparable over time, for example those expressed as a percentage of the total EU, then an explanatory note is presented with the series.

Additional time series are available from the other domains on National Accounts, in particular the domain on quarterly national accounts, and from Eurostat publications.

Most of the national data used in the calculation of the euro area and European Union aggregates have originally been published by the National Statistical Institutes (NSI). These data may also be used for cross-checking. Most are disseminated via the NSI's websites.

In certain cases, data from other domains of economic statistics, i.e. balance of payments statistics, business statistics, household budget statistics or external trade statistics can be used for cross-checking purposes. These economic statistics are also available from the appropriate domains on Eurostat's website.

In between Eurostat releases, Member States may revise their figures; Eurostat publishes the new Member States' accounts shortly after reception but does not recalculate the EU accounts until the next scheduled EU release. Geographical coherence may thus be lost for a brief period. In turn, a certain stability of annual aggregates is assured, and annual and quarterly EU aggregates will by default be coherent.

Not available.

National data are revised according to national schedules, and revisions are applied to Eurostat's online database as soon as they become available to Eurostat.

Figures for the annual European aggregates are revised at least twice per quarter, with the t+2 months and the t+9 months releases of quarterly accounts.  These dates are pre-announced in the release calendar on Eurostat's web-site (see 8.2). On these occasions, previously published figures are subject to revision for all variables and all quarters. Unless explicitly stated, no revisions are applied on the publication date of the flash estimate at t+45 days after the end of the quarter.

National accounts data are subject to continuous routine revisions as new input data becomes available. This will typically also entail revisions of the European aggregates, which are derived from these data, but updated estimations of the European aggregates are only released on specific dates. Annual data may be revised twice every quarter with the release of quarterly figures.

In addition, exceptional revisions will result from major changes in methodology. These major changes will be implemented with legislation, and therefore announced in the Official Journal of the European Union and other publications.

Eurostat publishes national accounts data for the European Union, euro area and country data (for EU Member States, EFTA countries, candidate countries, the United States, Japan and some other countries on an ad hoc basis). Eurostat estimates the figures for EU and euro area (see section below '18.5. Data Compilation' for details); all the other data are produced by the statistical offices of the respective countries.

Countries use many sources to compile their national accounts, among them administrative data from government, population censuses, business surveys and household surveys. No single survey can hence be referred to. Sources vary from country to country and may cover a large set of economic, social, financial and environmental items, which need not always be strictly related to national accounts. In any case, there is no single survey source for national accounts.

In particular, different sources are used for calculating the different approaches of GDP mentioned above under '3.4 Concepts and definitions'. If more than one of these approaches is used, their results are usually balanced, i.e. forced to be coherent, so that a single value for GDP is obtained.

For further information about sources and collection methods in National Statistical Institutes (NSIs), please refer to National Statistical Institutes and National Central Banks (see Eurostat's web site, and after having chosen the language to be used, select menu: All Services - Links and Contacts).

Member States should transmit national accounts data to Eurostat upon national publication and/or in line with the deadlines specified in the European System of Accounts (ESA 2012) transmission programme.  Member State's annual main aggregates are generally transmitted at t+2 and t+9 months.  For  further details see section 10.3 Dissemination format

Data are collected from national sources.  As the breadth of the sources varies, so does the frequency of collection, from monthly to annually, and in the case of population censuses they are mostly collected every decade. 

Data in ESA 2010 are transmitted via SDMX which introduced standardised codes.

National Accounts combine data from many source statistics. Techniques of data collection vary widely, depending on the compilation approach, the source statistics available, the particular account in the system of accounts, the timeliness of data release and other factors.

Source data undergo a sequence of checks within NSIs. Eurostat checks national data mainly for completeness (coverage of reference periods and variables) and consistency (accounting consistency, time-consistency between quarterly and annual accounts and consistency over time) and follows up with NSIs on any lack of quality in this respect.

The same checks are applied to data for the European aggregates. Validation against data from other domains and validation of the statistical tools used are done on an ad-hoc basis.

Eurostat compiles aggregate estimates for the euro area and the EU.  The annual current price data for the euro area and the EU are derived using Member States' data as input, usually by adding up the aggregates for all Member States after expressing them in a common currency (euros) .

EU chain-linked volumes are compiled from chain-linking EU data at previous year's prices, and not from summing Member States' chained series.

Figures expressed in Purchasing Power Standards are derived from figures expressed in national currency by using Purchasing Power Parities (PPP) as conversion factors.

Where single Member States' figures are not available, Eurostat may use unpublished estimates to impute country data and hence calculate the European aggregates.

If Member States' accounts show discrepancies (explicit or implicit) between GDP and the sum of components, European annual accounts derived from summing these up would show a discrepancy equal to the sum of Member States' discrepancies. To avoid this, European annual accounts use some variables to adjust for any possible lack of additivity between the total and the sum of its components, i.e. these variables are effectively used as balancing items. This is only possible at current and at previous year's prices, because of the lack of additivity induced by the chain-linking technique.

For the expenditure approach of GDP, the balancing variables are changes in inventories plus net acquisition of valuables (P.52+P.53).

For the income approach of GDP the balancing variables are gross operating surplus and mixed income (B.2g + B.3g). 

For the output approach of GDP, all elements are subject to a proportional adjustment.

Similarly, when calculating European aggregates, Eurostat corrects country data for lack of additivity if a variable does not equal the sum of its (industry, product or COICOP) breakdowns.

NSIs may provide explicit balancing adjustments for their national accounts. These are recorded as "discrepancy items" in the appropriate tables.

National Accounts figures, in contrast to foreign trade statistics, are not consolidated for intra-EU trade.

Due to different revision policy for the European aggregates and the Member States' data, there may be a difference between the European aggregate and the appropriate sum of national data between updates. Moreover, the European aggregates are not suitable for implicit derivation of values for missing national series.