Fear is mounting that the economic downturn in the US could turn into a deep and protracted recession of the kind that plagued Japan in the early 1990s,, driving policymakers and investors to consider whether increasingly radical measures may be needed to avert such an outcome.
This debate has superseded the old argument as to whether the US is in recession or not. Most economists now believe it is, following February's grim jobs report and evidence of stagnation in real consumer spending.
But a darker view has taken hold as the labour market started to crack, house price declines have intensified and financial markets deteriorated further until the Fed's latest liquidity operation.
Some analysts expect a double-dip recession, with growth fading again after a short-lived boost from the fiscal stimulus around midyear.