The Consumer Prices Index (CPI) and the Retail Prices Index (RPI) are the two main measures of consumer inflation in the UK. The Producer Price Index (PPI) measures the price changes of goods bought and sold by UK manufacturers. The Services Producer Price Index (SPPI) measures the price changes of services provided by UK businesses to other businesses and government.
Publications

Contains cost indices (purchase of materials and fuels, earnings and National Insurance, general expenses and combined costs) relating to four aerospace and electronics industries. The data are based on the revised Standard Industrial Classification SIC (2007) and are calculated on a base year of 2005=100. The indices are widely used by government and business as an authoritative source of information on inflation, cost adjusting and price variation in trading contracts.

The 'shopping basket' of items making up the Consumer Prices Index (CPI) and Retail Prices Index (RPI) are reviewed every year. Some items are taken out of the basket, some are brought in, to reflect changes in the market and to make sure the CPI and RPI are up to date and representative of consumer spending patterns. This article describes the review process and explains how and why the various items in the CPI and RPI baskets are chosen.

The Consumer Prices Index (CPI) and the Retail Prices Index (RPI) measure the changes from month to month in the cost of a representative 'basket' of goods and services bought by consumers within the UK. This involves weighting together price changes in the indices according to household spending patterns for different categories of goods and services so that each takes its appropriate share. At the beginning of each year the weights used to compile both the CPI and RPI are updated using the latest available information on household spending.

Contains price indices, percentage changes and weights for the Consumer Prices Index (CPI), Retail Prices Index (RPI) and the components that make up these indices. Internationally, the CPI is known as the Harmonised Index of Consumer Prices (HICP)

Covers the concepts underpinning the indices, differences between CPI and RPI, the methodologies used, collection and validation of prices, calculation of weights, and publication and usage of the different indices.

An analysis of trends in inflation since 1947 as measured by the Retail Prices Index (RPI).
Papers and a summary note from the Consumer Prices Advisory Committee meeting.
Corporate Services Price Index (CSPI) has been discontinued. Data is now available as the Services Producer Price Index (SPPI), a quarterly survey of prices charged for a range of services provided by businesses to other businesses and government.
The English Business Survey provides a high level view of business and economic conditions across the country over a range of backward and forward looking directional indicators including output, stocks, employment, labour costs, output prices, hours, capital investment and capacity constraints.

The purpose of this article is to give the estimated effects on the Consumer Prices Index and Retail Prices Index resulting from duty and taxation changes announced in the Budget. This article is simply a helpful guide to users of the CPI and RPI. The Office for National Statistics (ONS) accepts no liability whatsoever for losses of any kind arising as a result of reliance on this note.

The July 2011 edition of the Focus on Consumer Price Indices, is the final publication of data in this format. From 28 August 2011 all data published as part of the Consumer Price Indices Statistical Bulletin, will be published electronically via one Excel file on the Office for National Statistics website at: http://ons.gov.uk/ons/taxonomy/index.html?nscl=Consumer+Prices+Index
Harmonised Index of Consumer prices
The House Price Index (HPI) is a monthly output based on mortgage completions data from the Regulated Mortgage Survey (RMS). This release contains data on mix-adjusted average house prices and price indices, along with annual rates of change by region, type of buyer and whether a dwelling is new or pre-owned. A seasonally adjusted mix-adjusted house price index and monthly house price change are also included.
The House Price Index (HPI) is a monthly output based on mortgage completions data from the Regulated Mortgage Survey (RMS). This document contains user guidance related to the HPI.
The Index of Private Housing Rental Prices (IPHRP) is a quarterly experimental price index. It tracks the prices paid for renting property from private landlords in the UK.

This article describes CPIH - the new, additional measure of Consumer Price Inflation including owner occupiers' housing costs (OOH). The rental equivalence approach is used to measure OOH. The accompanying Excel file includes a back series for CPIH from 2005 to 2012.
The release includes an article which presents a method used to estimate a CPI series back to 1950. In addition the estimated series are provided at the all-items and two-digit CPI levels.

This publication is produced monthly by the Office for National Statistics for use by businesses preparing accounts in accordance with standard accounting practices. It contains price information for plant and machinery, and stocks, and all the asset-specific price indices likely to be useful for revaluing fixed assets.

A comprehensive selection of data on input and output index series. Contains producer price indices of materials and fuels purchased and output of manufacturing industry by broad sector.

Contains indices on UK manufactured products together with the materials and fuel purchased, and the home sales at both broad and detailed industry levels. The data are used throughout business and government.

Gives ONS' estimates of the relative differences in consumer prices between regions.
The Services Producer Price Index (SPPI) are primarily a suite of individual price indices that provide information on price change for a limited range of service industries. Each SPPI captures quarterly changes in the price received for services provided by UK businesses to other UK businesses and Government. These individual price indices are also aggregated together to create a 'service industry' SPPI with limited coverage.

The Services Producer Price Index (SPPI) are primarily a suite of individual price indices that provide information on price change for a limited range of service industries. Each SPPI captures quarterly changes in the price received for services provided by UK businesses to other UK businesses and Government. These individual price indices are also aggregated together to create a 'service industry' SPPI with limited coverage.
Overview
CPI and RPI
CPI and RPI measure change in the prices charged for goods and services bought for consumption in the UK. Prices are recorded monthly for a typical selection of products (referred to as the ‘basket of goods’) , using a large sample of shops and other outlets.
Each month price collectors record about 120,000 prices for over 650 goods and services. These prices are ‘weighted’ to ensure they reflect the relative importance of the items in the average shopping basket. The ‘basket’ is updated on an annual basis to ensure that the indices reflect UK consumer spending patterns.
After the price data have been processed, the Office for National Statistics (ONS) calculates an overall average price change, which forms the basis of the monthly CPI and RPI. These data are published each month on the National Statistics website in the form of a First Release, which contains relevant tables, texts and charts.
The PPI also works on the basket of goods concept, in two categories:
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output prices measure the change in the price of goods sold by UK manufacturers excluding VAT after any discounts, and
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input prices measure the change in price of goods bought by manufacturers for use in the manufacturing process
PPIs are published each month, with each release including tables, text and charts relating to each key measure.
The SPPI is based on one quarterly price survey. It uses similar concepts to the PPI, with representative services monitored over time.
Technical Data
What’s in the basket?
The contents of the CPI and RPI ‘baskets’ are fixed for a year. The CPI and RPI measure change in the total cost of the ‘basket’.
Most types of household spending are included. However, the CPI excludes many housing costs whereas the RPI includes these. There are several other differences between the CPI and the RPI.
Weighting
The quantity or ‘weight’ applied to each item in the basket reflects its relative importance in the typical household budget, based on average spending patterns.
The weights are derived from a number of sources but mainly from the Office for National Statistics’ (ONS')Expenditure and Food Survey (EFS), for RPI, and from household expenditure data within the national accounts for CPI. The weights are updated annually.
Calculating the CPI and RPI
Prices of each good and service are weighted together to produce the CPI and RPI indices. The inflation figure is usually shown as the percentage change between one month and the same month a year ago.
Changes in the price of the individual goods and services are measured by comparing them to their levels in the previous January. The indices are linked with the figures for earlier years. Only by ‘chain-linking’ the calculations in this way can the indices take account of changes in the make-up of the ‘basket’ from year to year, and provide like for like comparisons between different years.
Further details on all of the above, can be found in our Consumer Price Indices Technical Manual.
The Producer Price Index (PPI) Sample Design
The latest Products of the European Community (PRODCOM) sample is used as the main sampling frame for the PPI, from which a grouped random sample is drawn.
The PPI sample is re-selected annually from the latest PRODCOM sample in three phases. Information on PPI standard errors is published in the annual article on measuring standard errors in the PPI.
The Export and Import samples are cut-off samples that use HM Revenue & Customs trade data as their sampling frame.
Respondents to the price data surveys are recruited using a recruitment questionnaire. Each month, the current month’s price (with date of any price change) is requested with an option to provide prices up to three months in advance.
After collecting prices, a price relative is calculated. A price relative is the pure (quality adjusted) price of an item divided by its price in a given base year.
Raw price data are converted into a basic set of about a thousand price indices. From these, broader datasets are built up that reflect price trends of manufacturing input and output across whole industry sectors. These are currently defined using the 2007 Standard Industrial Classification (SIC) manufacturing divisions (10 to 33).
Weighting and Estimation
The PPI base year is reset (rebased) every five years to update weights used in the aggregation of the PPI.
Net sector weights are based on the results of the PRODCOM survey together with input/output tables, enabling transactions within the manufacturing sector to be excluded.
Statistical Disclosure
Statistical disclosure control methodology is applied to PPI data. This ensures that information attributable to an individual organisation is not disclosed in any publication.
Data coverage policy is to publish indices that meet our confidentiality criteria for publication.
Services Producer Price Index (SPPI) Sample Design
At present the SPPI survey comprises approximately 1,500 respondents and 4,500 items per quarter. The sample covers Great Britain and is selected from a fixed panel.
Raw price data are converted into a basic set of around 30 price indices. These are currently defined using the 1992 SIC, and will be reclassified onto SIC 2007 in 2010. Higher-level weights are based on the quinquennial SPPI turnover survey.
Glossary
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Annual Business Inquiry (ABI)
An integrated survey of employment and accounting information from businesses and other establishments in most industry sectors of the economy.
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Base year
The time period from which relative levels are measured and which is usually allocated the value of 100 in an index.
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Chain-linking
A method of constructing an index series from two or more index series of different base periods or different weights.
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Classification of Products by Activity (CPA)
Provides lists of products under each economic activity.
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CPI
Consumer Prices Index. The Government-preferred measure of UK inflation.
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Export prices
Measures the change in price of goods exported by UK manufacturers.
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First Release
An Office for National Statistics (ONS) term given to the first official release of ONS data.
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Focus on Consumer Price Indices
An Office for National Statistics publication that gives further historic detail and data for the UK CPIs.
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Gross sector
Measures the price of products sold by UK manufacturers irrespective of the classification of the customer who buys the product.
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HICP
Harmonised Index of Consumer Prices. A comparable measure of inflation for Member States of the EU. In the UK, the HICP is known as the CPI.
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Import prices
Measures the change in price of goods imported by UK manufacturers.
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Index
A set of numbers that measure the same characteristics and are all expressed relative to the same reference period or location. (The reference period or location is called the base and often set at 100.) An index provides a representative series of numbers used to indicate trends in prices, production and other variables.
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Input/output tables
An accounting framework for all transactions in the UK.
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Input prices
This measures the change in price of goods bought by manufacturers for use in the manufacturing process.
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Net sector
Measures the change in price of products manufactured in the UK but sold outside the manufacturing sector.
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Output prices
Measures the change in the price of goods sold by UK manufacturers net of VAT, after any discounts.
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Producer Price Indices (PPI)
Measures the price changes of goods bought and sold by UK manufacturers.
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Products of the European Community (PRODCOM)
A Eurostat survey into manufacturing production.
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RPI
Retail Prices Index. The RPI is used in the revisions of tax allowances, state benefits, pensions and many other types of payment. It provides a longer run of data than CPI, with the index available back to 1947.
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RPIX
Retail Prices Index excluding Mortgage Interest Payments (MIPS). An aggregate of the RPI produced to show an estimate of the RPI minus the effect of MIPS.
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Services Producer Price Indices (SPPI)
Measures the price changes of services provided by UK businesses to other businesses and government. It is an experimental index.
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Standard Industrial Classification (SIC)
A way of categorising economic activities into a common structure.
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Stratified random sampling
Sampling from a population that has been divided into subsets, with part of the sample coming from each subset.
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UK
United Kingdom. The nation state consisting of England, Scotland, Wales and Northern Ireland.
Contact Details
For statistical enquiries about this topic, please contact:
CPI/RPI enquiries
Email: cpi@ons.gsi.gov.uk
Telephone: +44 (0) 1633 456900