The Office for National Statistics compiles data on consumer prices. Each month around 120,000 separate price quotations are collected for around 650 items which make up the Consumer Prices Index (CPI) and the Retail Price Index (RPI) `basket' of goods and services. The selection of items to be priced is partly based on the findings of the Expenditure and Food Survey (EFS). The weights attached to items for the RPI are largely based on the EFS, which the CPI weight are largely based on the National Accounts data.

The main use of the data is to calculate the CPI and the RPI. Both indices measure the average change month to month in the prices of consumer goods and services purchased in the UK. The CPI is the main UK domestic measure of inflation for macroeconomic purposes. The use...

More Source information to be found here ...