Consumer Price Indices: Frequently Asked Questions (FAQs)

CPIs can be downloaded from OECD Consumer Price Indices (CPIs) Database via the OECD Data Explorer:

• Consumer price indices (CPIs, HICPs), COICOP 1999;
• Consumer price indices (CPIs), COICOP 2018 (for countries for which data are available according to the COICOP 2018).

In OECD Data Explorer,  methodological information is attached to each CPI series published flagged, by this small blue icon 

CPIs are monthly data except in Australia and New-Zealand which publish quarterly CPI data..

The OECD updates CPIs series for OECD member countries and other major non-OECD economies in real-time, following the CPI release calendar of respective country. The IMF provides the advance CPI release calendar.

The OECD CPI news release is published each month when CPI data for the reference month have been released by all OECD countries (usually at the end of the month, following the reference month). See the release dates.

The OECD Zones (OECD Total, OECD-Europe, Major seven and G20) are revised each month due to the revisions of the National Accounts and the PPPs.

The OECD publishes non-seasonally adjusted national CPIs that are not usually revised. However, national CPIs published by the OECD could be revised for the two following reasons:

1. In few countries (e.g. Austria) there is an explicit revision policy to publish a preliminary CPI and then revised the index after some fixed periods (usually one to three months).
2. The national reference period of CPIs is subject to change every 5 years on average in OECD Member countries. Data providers could introduce at the same time methodological changes or/and new basket of products. These changes can lead to revisions of the series published by the OECD.

The OECD publishes CPIs following the COICOP Classification:

• CPI All Items (COICOP 01-12) and its breakdown in 12 COICOP Divisions. Several additional classes are available, as well (e.g. COICOP 04.5, Electricity, gas and other fuels & 07.2.2, Fuels and lubricants for personal transport, used to calculate CPI Energy):
• CPI series for special groups which are of particular importance for household consumption such as Energy, Housing and Services.

The OECD publishes CPI series with the objective of compiling comparable CPI data across countries, analytically useful, timely and when possible, with long historical series. National Statistical Offices in OECD countries are progressively moving from the COICOP 1999 classification to the COICOP 2018, which is the most recent version. Following CPI series are available in "Consumer Price Indices (CPIs)" datasets in OECD Data Explorer:

For countries for which data are available according to the COICOP 1999:

1. CPI All Items (COICOP 01-12);
2. CPI Energy (COICOP 04.5, Electricity, gas and other fuels & 07.2.2, Fuels and lubricants for personal transport);
3. CPI All items less food less energy (COICOP 01-12 less COICOP 01, 04.5 & 07.2.2);
4. CPI Housing (COICOP 04.1, Actual rentals for housing, COICOP 04.2, Imputed rentals for housing & COICOP 04.3, Maintenance and repair of the dwelling);
5. CPI Services less housing (Services less COICOP 04.1, Actual rentals for housing, 04.2, Imputed rentals for housing, & 04.3.2, Services for the maintenance and repair of the dwelling);
6. CPI Services (Services as defined by COICOP);
7. CPI Goods (Non-durable, semi-durable, and durable goods as defined by COICOP);
8. CPI Food and non-Alcoholic beverages (COICOP 01);
9. CPI Alcoholic beverages, tobacco and narcotics (COICOP 02);
10. CPI Clothing and footwear (COICOP 03);
11. CPI Housing, water, electricity, gas and other fuels (COICOP 04);

i.   CPI Actual rentals for housing (COICOP 04.1);
ii.  CPI Imputed rentals for housing (COICOP 04.2);
iii. CPI Maintenance & repairs of the dwellings (COICOP 04.3);
iv. CPI Water supply and miscellaneous services relating to the dwelling (COICOP 04.4);
v.  CPI Electricity, gas and other fuels (COICOP 04.5);

12. CPI Furnishings, household equipment and routine household maintenance (COICOP 05);
13. CPI Health (COICOP 06);
14. CPI Transport (COICOP 07);

i.  CPI Fuels and lubricants for personal transport equipment (COICOP 07.2.2);

15. CPI Communication (COICOP 08);
16. CPI Recreation and culture (COICOP 09);
17. CPI Education (COICOP 10);
18. CPI Restaurants and hotels (COICOP 11);
19. CPI Miscellaneous goods and services (COICOP 12) 

For countries for which data are available according to the COICOP 2018:

1. CPI All Items (COICOP 01-13);
2. CPI Energy (COICOP 04.5, Electricity, gas and other fuels & 07.2.2, Fuels and lubricants for personal transport);
3. CPI All items less food less energy (COICOP 01-12 less COICOP 01, 04.5 & 07.2.2);
4. CPI Housing (COICOP 04.1, Actual rentals for housing, COICOP 04.2, Imputed rentals for housing & COICOP 04.3, Maintenance and repair of the dwelling);
5. CPI Services less housing (Services less COICOP 04.1, Actual rentals for housing, 04.2, Imputed rentals for housing, & 04.3.2, Services for the maintenance and repair of the dwelling);
6 . CPI Services (Services as defined by COICOP);
7. CPI Goods (Non-durable, semi-durable, and durable goods as defined by COICOP);
8. CPI Food and non-Alcoholic beverages (COICOP 01);
9. CPI Alcoholic beverages, tobacco and narcotics (COICOP 02);
10. CPI Clothing and footwear (COICOP 03);
11. CPI Housing, water, electricity, gas and other fuels (COICOP 04);

i.   CPI Actual rentals for housing (COICOP 04.1);
ii.  CPI Imputed rentals for housing (COICOP 04.2);
iii. CPI Maintenance, repair and security of the dwelling (COICOP 04.3);
iv. CPI Water supply and miscellaneous services relating to the dwelling (COICOP 04.4);
v.  CPI Electricity, gas and other fuels (COICOP 04.5);

12. CPI Furnishings, household equipment and routine household maintenance (COICOP 05);
13. CPI Health (COICOP 06);
14. CPI Transport (COICOP 07);

i.  CPI Fuels and lubricants for personal transport equipment (COICOP 07.2.2);

15. CPI Information and communication (COICOP 08);
16 CPI Recreation, sport and culture (COICOP 09);
17. CPI Education (COICOP 10);
18. CPI Restaurants and accommodation services (COICOP 11);
19. CPI Insurance and financial services (COICOP 12)
20. CPI Personal care, social protection and miscellaneous goods and services (COICOP 13)

The "National CPI Weights" dataset contains the annual expenditure weights for the national CPI for the OECD Member countries at a detailed level of the COICOP classification.

The weight of a product in a CPI is the proportion of total household expenditure which is spent on that product during the weight reference period. The weights reported under year 'y-1' are those used for the computation of CPIs in year 'y' (e.g. the weights reported for the year 2022 are those used for the computation of CPIs in 2023).

National CPI weights are expressed in "Per thousand of the National CPI Total". They are available in the OECD Data Explorer:

• National CPI, Item weights, COICOP 1999, All countries, All items;
• National CPI, Item weights, COICOP 2018, All countries, All items

The contributions to annual inflation show, how much each of the COICOP Division contributes to the annual inflation for a given month. They are expressed in percentage points of annual inflation rate.

Contributions to annual inflation for OECD member countries (except Australia) are available in the dataset: "Consumer Price Indices (CPIs)" on OECD.Stat. Contributions are available for 12 COICOP Divisions, some COICOP classes and special group such as Energy and Housing.

All data are calculated by the OECD except for Austria, Chile, Finland, Mexico, the Netherlands, Poland, Sweden, and the United Kingdom where data is provided by the National Statistical Offices. Contributions calculated by the OECD are based on Ribe formula. Further methodological information on compilation of the contributions to annual inflation can be found in the OECD calculation of contributions to overall annual inflation (PDF). 

Contributions to annual inflation are available in the OECD Data Explorer in

• Contribution to year-on-year inflation by COICOP 2018 by country or
• Contribution to year-on-year inflation by COICOP 1999 by country.

Eurostat, the statistical office of the European Union publishes the Harmonized Indices of Consumer Prices (HICPs), calculated according to a harmonised approach and a single set of definitions in order to give comparable measures of inflation in the euro area, the European Union, the European Economic Area and for other countries including accession and candidate countries. They provide the official measure of consumer price inflation in the euro area for the purposes of monetary policy in the euro area and assessing inflation convergence as required under the Maastricht criteria. Further information on HICPs methodology and HICP data can be found on the Eurostat website.

HICPs for European countries, Euro Area and European Union are also available in the OECD Data Explorer in Eurostat harmonised index of consumer prices (HICP). 

The CPI series published by the OECD are National Consumer Price Indices computed by National Statistical Office (NSO) of OECD member countries following their own methodology. The OECD zones (OECD Total, OECD-Europe and Major seven) are computed by the OECD using National CPIs.

Following three OECD zones are calculated with data going back to January 1970:

1. OECD-Total to the 38 OECD countries, starting from 1995. Prior to 1995 Chile, Colombia, Costa Rica, Czechia, Estonia, Hungary, Iceland, Israel, Latvia, Lithuania, Poland, Slovak Republic, and Slovenia are excluded.
2. OECD-Europe refers to the 26 OECD European countries, starting from 1995. Prior to 1995, Czechia, Estonia, Hungary, Latvia, Lithuania, Poland, Slovak Republic and Slovenia are excluded;
3. G7 - Major Seven refers to the seven major countries: Canada, the United-States, Japan, France, Germany, Italy and the United Kingdom.

The OECD Zones are calculated for the four following CPI series:

1.  CPI All items;
2. CPI Food and non-alcoholic beverages;
3. CPI Energy;
4. CPI All items less food less energy.
   

The OECD Zones for CPI are annually chain-linked Laspeyres indices. The weights for each individual link are based on the previous year's private final consumption expenditure of Households and Non-profits institution serving Households expressed in purchasing power parities (PPP). 

Hence, OECD Zone aggregates are subject to revisions as a result of revisions of the national accounts and the PPPs. Usually, new weights for the most recent complete year are incorporated in either November or December of each year. See country weights in percentage of OECD Total.

The G-20 area aggregate is calculated for the headline indicator only (CPI/HICP All items). It uses national CPIs for all G-20 member countries (with the exception of Türkiye and the United Kingdom) not being part of the EU, while it uses the HICPs for Member States of the EU and for Türkiye and the United Kingdom.

The G-20 area consists of the following economies: Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, the Russian Federation, Saudi Arabia, South Africa, Türkiye, the United Kingdom, the United States, and the European Union.

From January 2018 onwards, the officially reported CPI-series for Argentina was included in the G-20 area aggregate. The inclusion of the Argentinian CPI in the G-20 area aggregate entailed a clear break in the series.

The G-20 aggregate is calculated in the same way as the OECD Zones taking the sixteen individual country members of the G-20 (other than France, Germany and Italy) plus the EU as an aggregate. Download further methodological information on compilation of the G-20 CPI aggregate (PDF).

Data related to G-20 area are available in the OECD Data Explorer.

All CPI series are published by the OECD with 2015=100 as reference year to facilitate comparisons across countries. National providers may calculate indices using a different reference period (e.g. Canada publishes CPI with 2002=100 as reference year); they are re-referenced by the OECD to 2015=100. 

The OECD calculates and publishes also the movements of price indexes from one month to another expressed as percent changes: Percentage change on the same period of the previous year and Percentage change on the previous period. An advantage of calculating percent changes is that the result will be the same no matter what reference period is specified.

Following five measures for CPI series are available (for Annual, Quarterly and Monthly data):

1. Index with 2015=100 as reference year;
2. Annual change: Percentage change on the same period of the previous year (%);
   
3. Previous period change: Percentage change on the previous period (%)
4. Same period of the previous year change: Percentage change on the same period of the previous year (%
5. Contribution to annual inflation: Percentage point (%).

In addition, the annual National CPI Weights are published in measure: Per thousand of the National CPI Total. 

For a limited number of countries (Australia, Canada, France, Germany, Japan and the United States) seasonally adjusted series (Index 2015=100) are available on OECD.Stat. Seasonally adjusted series are subject to revisions.

CPIs are indices expressed with a fixed reference year (2015=100) and by definition are not expressed in a specific currency. However, prices of a transaction collected to calculate CPIs are expressed in national currency.

More information on national CPIs can be found on:

1. Detailed methodological information on CPI for OECD countries
   
2. The NSOs websites.

More comprehensive information and explanations for compiling CPIs are provided by: 

1. The Consumer Price Index Manual– Theory and Practice, International Labour Office, Geneva, 2004. 
2. The Practical Guide to producing Consumer Price Indices, United Nations, New-York and Geneva, 2009.