This week’s Budget, like its predecessors, assumes a sizeable fiscal squeeze in the years ahead. On the OBR’s numbers, the primary balance (tax receipts minus spending on everything except debt interest) is forecast to improve by 3 per cent of GDP over the next 5 years, from a deficit of 1.5 per cent in 2025-26 to a surplus of the same size by 2030-31. The IMF singled the UK out this month as one of the few advanced economies where action on the deficit has been taken decisively. The trouble is that few people outside the Fund expect this squeeze to be delivered. [...]