Back to top
Reference metadata

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.

For more information, please consult our metadata website section.

Close

Correction coefficients in the European Union (Duty stations) - index (Brussels = 100) (prc_colc_tot)

Reference Metadata in Euro SDMX Metadata Structure (ESMS)

Compiling agency: Eurostat, the statistical office of the European Union

Need help? Contact the Eurostat user support


Short metadata
Full metadata

Correction coefficients (duty stations) are used to ensure equality of purchasing power of remuneration between different locations within the European Union and Brussels.

Correction coefficients are calculated as the ratio between the "economic parity" and the exchange rate to the Euro (where applicable). They operate as a percentage adjustment to remuneration expressed in local currency.

 

As the correction coefficient is simply the economic parity divided by the exchange rate, it can be seen that the exchange rate effect cancels out and the economic parity is the appropriate conversion rate to convert amounts expressed in local currency into Euro and eliminate the effect of price level differences.

The economic parity tells us how many currency units a given quantity of goods and services costs in different duty stations. 

The method used to establish economic parities is to compare the price of a basket of goods and services purchased by the average international official in Brussels with the price of an equivalent basket of goods and services purchased by the average international official in each of the other duty stations.

To compile these prices, Eurostat carries out a number of detailed price surveys in cooperation with national statistical institutes. This data is also re-used for the similar exercise to establish CC for retired staff in EU Member States (see prc_colc_nat).

For each item, the price ratio with Brussels is computed. Similar items are grouped into "basic headings", and a geometric mean of the price ratios is calculated to establish a basic heading parity. These basic heading parities are then aggregated to produce an overall parity. This aggregate is computed as a weighted arithmetic mean, using consumption expenditure pattern of active international officials as weights.

11 October 2022

See also section 18.1

a) Bilateral economic parities

In their simplest form economic parities are price relatives that show the ratio of the prices in national currencies of the same good or service in different countries. For example, if the price of a hamburger in Brussels is 3.11 Euros and in Copenhagen the price is 30.57 Krone, then the parity for hamburgers between Copenhagen and Brussels is 30.57 Krone to 3.11 Euros, or 9.830 Krone to the Euro. This means that for every Euro spent on hamburgers in Brussels, 9.830 Krone would have to be spent in Copenhagen to obtain the same quantity and quality - or, in other words, the same volume - of hamburgers.

If hamburgers were the only item of consumption in the basket of goods and services, then to ensure equivalent purchasing power of the Euro remuneration of a Brussels-based international official when working in Copenhagen, the remuneration should either be converted into Krone using the economic parity directly - or the remuneration should be multiplied by the exchange rate between the Euro and the Krone and then multiplied by the correction coefficient.

In practice the parity at the level of the overall aggregate refers to a complex assortment of goods and services. Thus, if the total parity (ie. the parity for total remuneration) between Copenhagen and Brussels is 9.830 Krone to the Euro, it can be inferred that for every Euro received and spent in Brussels, 9.830 Krone would have to be spent in Copenhagen to purchase the same volume of goods and services. Purchasing the same volume of goods and services does not mean that baskets of goods and services will necessarily be exactly identical in both countries. The exact composition of the baskets will vary to reflect differences in tastes and cultural backgrounds, but both baskets will, in principle, provide equivalent satisfaction or utility.

b) Consumer goods and services

Survey price data is compiled in accordance with Regulation 1445/2007 and the Eurostat-OECD manual on purchasing power parities.

Updating indices (the Harmonised Index of Consumer Prices) are obtained from national statistical institutes.

This data is also re-used for the similar exercise to establish CC for retired staff in EU Member States (see prc_colc_nat).

c) Housing

Housing costs are treated differently from other prices mainly for two reasons:

  • They are typically the largest single item of expenditure in the basket (at least 20-25% of total consumption)
  • Housing is different from other consumer goods and services because no two dwellings are exactly alike, especially when taking into account all secondary attributes which have an impact on price such as location, infrastructure, etc.

For this reason, a six year moving average model is implemented, for which specific rent surveys are conducted annually by national statistical institutes in cooperation with Eurostat and other international organisations.

This data is also re-used for the similar exercise to establish CC for retired staff in EU Member States (see prc_colc_nat).

d) Education and Healthcare

Member States have developed different delivery systems for these services, and there is typically special treatment of such expenditures for international officials because the needs of expatriates can vary from those of the national population. For this reason, a specific methodology is implemented, involving direct surveys. A survey of private school fees and university fees is organised every three years.

This data is also re-used for the similar exercise to establish CC for retired staff in EU Member States (see prc_colc_nat).

e) Consumption expenditure patterns

These are established on the basis of direct household expenditure surveys ("family budget surveys") conducted at periodic intervals amongst international officials. The average result for each duty station is established as the consumption pattern until the next survey. Where the population of international officials is particularly small or mobile or response rates are particularly low, such that a reliable structure cannot be established, a regional pool weight may instead be applied.

Correction coefficients (duty stations) are established for the specific duty station location.

The classification of retail outlets used in the European Comparison Programme applies for pricing purposes.

For dwellings the specific classification developed for the moving average model applies; prices are compiled from real estate agencies.

For consumption expenditure patterns, the households of individual international officials.

Pricing samples are selected from the full market of goods and services.

Consumption expenditure survey participants are selected from the total population of international officials.

Correction coefficients (duty stations) are established for the capital cities of the EU member states, including UK until 2020, except Netherlands where The Hague is used instead of Amsterdam. In addition they are established for selected locations in Germany (Bonn, Karlsruhe, Munich) and Italy (Varese), and in UK (Culham) until 2020 and Germany (Bonn) until 2021.

The Staff Regulations set out specific rules for the creation, and cancellation, of duty station locations for which a specific correction coefficient applies. For any other duty stations within the Member State, the capital city value applies.

No correction coefficient is applied for Luxembourg as, in accordance with the Staff Regulations, the price level is deemed equal to that in Brussels.

Correction coefficients (duty stations) are updated yearly with reference to June (1st July).

A second calculation with reference to December (1st January) is done to identify any duty stations where the movement since the preceding June exceeds a threshold specified in the Staff Regulations.

The precision of parities, and therefore the precision of correction coefficients, increases with the level of aggregation. This means that the parity at the level of total household consumption will be more reliable, or precise, than the parity for "food and non-alcoholic beverages" which is one of the sub-aggregates of final household consumption (12 main COICOP groups). Similarly, the parity for "food and non-alcoholic beverages" will be more reliable than the parity for "bread and cereals" which is one of the analytical categories within that COICOP group.

The input data into the parity calculation process comes from several sources, specifically, from special price surveys of consumer goods and services, and special surveys of household consumption expenditure. This makes it impossible to calculate any meaningful, numerical measure of error margins for parities.

Correction coefficients (duty stations) are expressed as a percentage.

The correction coefficients are the mathematical ratio between the economic parity and the exchange rate. Parities and exchange rates express the number of currency units per Euro.

The calculation of the overall parity involves three stages. 

a) At the level of each individual item, price observations are averaged (simple arithmetic mean). These average prices are then used to calculate a price ratio relative to Brussels.

b) At the basic heading level, the price ratios for all items in that group are averaged (simple geometric mean).

c) Finally, the basic heading parities are aggregated (weighted arithmetic mean) using the basic heading expenditure weights.

Survey prices for consumer goods and services except housing rents and education, are obtained from the European Comparison Programme and these are updated until the next survey of the same type using the detailed subindices of the Harmonised Indices of Consumer Prices. Item samples are determined by Eurostat in collaboration with Member States and the OECD. The final selection should be comprised of comparable items and, to the largest extent possible, be equally representatives of the consumption expenditure patterns in participant countries. Subsequent data collection is conducted by national statistical institutes.

Duty station rent prices are obtained from specific surveys of real estate agencies coordinated by Eurostat and the International Service for Remunerations and Pensions of the Coordinated Organisations.

Cost data for European Schools and price data for private schools is obtained by direct surveys. Price data for universities is obtained from Eurydice annual report.

Expenditure weights for aggregation purposes are obtained from periodic family budget surveys conducted amongst international officials.

Yearly

Correction coefficients for June (1st July) are published in autumn of the same year.

Correction coefficients are specifically designed as spatial price level indicators, and the comparability of the results across countries can be assumed to be very good. 

Correction coefficients are designed to compare price levels for different geographical locations at the same point in time. Temporal consumer price indices on the other hand are designed to compare price levels for the same geographical location at different points in time. This difference has important implications for the way in which items are selected and defined, and other aspects of methodology. It is conceivable that two successive calculations of correction coefficients may use quite different samples and methodologies, if this is considered necessary to produce a spatial comparison of improved quality. Unfortunately, no indicator exists that simultaneously captures spatial and temporal aspects in an adequate manner. Clearly a degree of care is therefore required when interpreting the temporal development of correction coefficients.