United Kingdom - Consumer Price Index (CPI)

For the U.K., a detailed consumer price index (viz., a European harmonized CPI), and analytic variants thereof.

The source writes:

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 Producer Prices Indices (PPIs) measure the prices of goods bought and sold by UK manufacturers. The headline measure, known as factory gate inflation, measures the price of the goods UK manufacturers charge other UK businesses for their products. This is great if you own a factory or want to understand how this part of the economy is performing, but not so useful if you want to understand the pressures on your own personal budget.
• Service Producer Price Indice (SPPIS) do a similar job for the service industry sector, and have similar types of use to PPIs, but from a service sector perspective.
• For private households, there are the Consumer Prices Index (CPI) and Retail Prices Index (RPI). From March 2013, ONS will also publish a new measure, CPIH, which includes owner occupiers’ housing costs which are excluded from the CPI.

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.

• Framework: Eurostat harmonized CPI
• Classification: COICOP
• Measurements:
  • Fixed-base index relative to January 1987 (Index Jan1987=100)
  • Relative to 1995 (Index 1995=100)
  • Relative to 2015 (Index 2015=100)
  • Percent change year-over-year (% Y/Y)
  • Percent change month-over-month (% M/M)
  • British pounds (GBP) per product-specific units
  • British pence (1/100 GBP) per product-specific units
• Adjustment: Not seasonally adjusted (NSA)
• Native frequencies:
  • Monthly
  • Quarterly
  • Annual
• Start date:

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:

http://www.statistics.gov.uk/cci/article.asp?id=1991

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. 

Moody's Analytics supplements

We produce SA versions of select CPI components.

The source (ONS) reports a "Harmonised Index of Consumer Prices (HICP)" and a "Consumer Prices Index including owner occupiers' housing costs (CPIH)". Under Data Buffet termonology, the former is abbreviated "CPI-H."

Further reading

At IMF (SDDS):

• Price index - Consumer prices
• Price index - Retail Price Index