Among them, hybrid weakness is definable as weak growth occurring in F1 hybrids derived from crosses between two normal strains.
"The weakness in growth will continue to hold down employment growth," O'Sullivan said.
It describes the root causes of pervasive weakness in growth as "persistent financial market fragmentation, weak bank balance sheets, low demand, and creeping uncertainty as well as structural weaknesses, all reinforce each other and contribute to contraction of real activity".
In a downbeat assessment of the prospects for the economy, the Paris-based OECD said Threadneedle Street would have to steadily increase borrowing costs over the next 18 months despite the weakness of growth.
It said any sign of weakness in growth should be met with higher spending by the Treasury.
Moody's, a credit-rating agency, downgraded the country's debt from AAA to AA1, citing "continuing weakness" in growth.
The Fed said it now viewed the risks to the economy as evenly balanced between sustained weakness and growth so strong that it could ignite inflation.
"The Fed found a whole bunch of different adjectives to describe weakness in growth, and a whole bunch of adjectives to describe price pressures," said Ethan Harris, chief economist of the investment bank Lehman Brothers.
"The balance of risks is still tilted toward weakness in growth and employment, and not toward higher inflation," said William C. Dudley, president of the Federal Reserve Bank of New York, in a speech on July 29.
"While at first glance this looks a decent performance, in actual fact it would represent a far from dynamic performance after the weather-influenced contraction of 0.5% in the fourth quarter of 2010... just as the fourth quarter 2010 contraction overstated the economy's weakness, so growth in the first quarter of 2011 will highly likely overstate its strength," Archer said.
