Let's suggest we cut the great depression in two pieces
The contraction and the mid term aftermath
Thesis part two started in the summer of '33
And the system found ways to move unemployment  back down near  to
10% not far north of where we are now in the  great recession
Of course without a robust transfer system /safety net 
The new deal had to sop up huge numbers of the unemployed with wpa ops to move
The system to this socially tolerable unemployment rate range
Where it hung fire
 more or less 
till the second po.icy induced  contraction of '37 
Which itself was goosed ...now by more like Keynesian methods back up to the 10%
tolerable range again
Until the toal game changerafter september39
 Kicked us into the full bore arsenal of democracy gig  
  
Conclusion the acceptable range has remarkably changed little in the present era from what it was in the prior era 
We can tolerate around one out of ten candidates for a job to languish protractedly 
In a jobless state