One component did much of the work in September’s US inflation figures. Petrol prices jumped 9.1% from August, accounting for more than half of the overall monthly increase. The seasonally adjusted consumer price index was up 0.6%, following a 0.4% rise in August. On an unadjusted basis, prices were 3.7% higher than a year earlier.
The supermarket told a different story. Food bought to eat at home cost 0.1% less than in August, while food purchased away from home cost 0.2% more. The overall food index was flat. Two households buying much the same groceries could therefore have experienced quite different changes to their budgets depending on how far they had to drive.
Prices excluding food and energy rose 0.3% on the month, the same pace as in August. The petrol increase helps explain the acceleration in the headline figure, but does not account for all the price pressures elsewhere in the basket.