If the rate of retail price inflation is 4 per cent and if the regulator feels that firms ought to be able to achieve cost savings of 6 per cent over the coming 12 months, then, under an RPI-X system of price regulation, firms must
◦ not raise prices by more than 10 per cent.
◦ reduce prices by 6 per cent.
◦ not raise prices by more than 2 per cent.
◦ not raise prices by more than 4 per cent this year and reduce them by 6 per cent next year.
◦ reduce prices by 2 per cent.