2 Divergence between WPI and CPI 8. Why do WPI and CPIs differ? They differ in terms of their weighting pattern. First, food has a larger weight in CPI ranging from 46 per cent in CPI-IW to 69 per cent in CPI-AL whereas it has a weight of only 27 per cent 3 in WPI.
It is important that this is perceived - and lastingly perceived - to be the case in all the participating countries. Otherwise, political conflicts might impose a heavy burden on monetary union at a later date. The task of preserving a durably stable currency is, however, one which has to be faced in other policy areas, too.