The government, or rather the Bank of England (in collusion with the macro-economic objectives of govt economic policy) sets the RPI.

It has long been a fix, considering that the price of mortgages is specifically excluded. However, it also ignores fuel prices, house prices, community charges, all the items that are significant parts of the average persons monthly bills, all of which are increasing considerably above the official RPI.

so the RPI is a useless indicator of the change in  people's financial needs. But, as you say, employers, including the govt, like it cos it keeps their costs down.

keep to the Fen Causeway