asked the Chancellor of the Exchequer what would be the effect on the retail price index of an increase of 5 per cent. on the price of derv, setting out the effect on the retail price index after one month, two months, three months, six months, one year and two years, respectively.
[pursuant to his reply, 26 June 1980]: Derv does not enter the RPI directly. An increase in derv will, however, raise industrial costs, but the impact of these higher costs on prices is uncertain. The effects of such an increase can be examined using the Treasury model, which is available for hon. Members' use via the House of Commons Library.