|Unit||Index 2015=100, NSA|
|Adjustments||Not Seasonally Adjusted|
Consumer Price Indices (CPI), is the main UK domestic measure of inflation for macroeconomic purposes. The CPI is a measure of consumer price inflation produced to international standards and in line with European regulations. First published in 1997 as the Harmonised Index of Consumer Prices (HICP), the CPI is the inflation measure used in the Government’s target for inflation.
The ONS publishes a range of measures of consumer price and other price inflation, all of which measure the inflation for different groups of people or products.
The multiple measures for private households bring us on to the second reason for producing a range of measures – what do you want to do with your measure of inflation? The CPI has been designed to provide a comparable measure of inflation across Europe. Having been designed to be comparable, it has also been designed in line with best international standards for measuring the inflation of private households.
The RPI has been around a lot longer than the CPI (it dates back to the 1940s). The RPI has many long-term users and ONS is required to produce it under UK law. The National Statistician recently announced that the RPI does not meet best international standards because of a formula used in its calculation. Therefore a new index called RPIJ, which uses another formula (called Jevons) in its calculation, will be published from March 2013. In recognition of the value to users in maintaining continuity, the RPI will continue to be published too.
The CPI and the RPI are compiled using the same underlying price data, and are based on a large and representative selection of around 650 individual goods and services for which price movements are measured in around 150 randomly selected areas throughout the UK. Around 120,000 separate price quotations are used every month to compile the indices. The outlets in which the prices are collected are selected randomly. Expenditure weights are held constant for one year at a time. The selection of goods and services that are priced to compile the CPI and RPI is reviewed annually. The contents of the 2008 basket are described in an article published on the National Statistics website at: http://www.statistics.gov.uk/cci/article.asp?ID=1951 The expenditure weights used to compile the indices are also updated each year. Additional details of the updated CPI and RPI weights for 2008 are available from the National Statistics website in an article entitled Consumer Prices Index and Retail Prices Index: Updating Weights for 2008:
Rates of change for the CPI are calculated from unrounded index levels, rather than on the published indices, which are rounded to one decimal place. The use of unrounded indices increases the accuracy of the calculation. The unrounded index levels are available on request. By contrast, rates of change for the RPI are calculated from the published rounded indices. Starting January 2016, the indices are based to 2015=100.
The data is subject to revisions.
For futher information, please follow: https://www.ons.gov.uk/economy