US Birth Rate drops to record low in 2011 - a chart !

[opebo]

I do believe there is a great deal of deferred 'household formation' - marriage, reproduction, and yes, even sex, during periods of severe economic decline. 

[opebo]

The recession probably is the main culprit. The days when children were an economic asset are long gone.

Actually this aspect could come back.  The new (and likely to be endemic) poverty and the lack of any social safety net envisioned by austerity advocates should eventually make having more children and using them in some remunerative employment a net plus for poors, as was the case before the Keynesian/redistributionist/unionist experiment.