Specifically, the question is not whether it can grow, but whether it can grow fast enough to propel a large economy that, according to the US Federal Reserve, faces “balance-sheet deleveraging, credit constraints, and household and business uncertainty about the economic outlook.” And, remember, it is just over a year since certain US officials were proclaiming the economy’s “summer of recovery” – a view underpinned by the erroneous belief that America was reaching “escape velocity.”