For anxious Americans worried about their homes and their jobs, there has at least been one piece of good news this summer: the price of petrol has fallen about 40 cents from its peak of more than $3.20 a gallon.

The fall is a consequence of an easing in the shortage of US refinery capacity and a drop in the price of crude, which is down about 9 per cent from its peak of $78.77 for West Texas Intermediate at the beginning of the month.