A 0 to 3 percent range seems a reasonable compromise. But whether there is any benefit at all from a wider target band depends significantly on how a wider band, with a higher ‘ceiling’, affects the public’s expectations of future inflation.
If people understand the new target as meaning that the Bank, under Government instructions, is now willing to accept 1 percent more inflation than previously, then nothing positive will have been achieved at all - and indeed there will almost certainly be net cost involved in the change.