SS Projection Uncertainty and Recessions

In a post at Angry Bear Bruce Webb counters someone's claim that the recession is going to force us to deal with changes to SS sooner. My thoughts (on accuracy of projections) require looking at this chart which is drawn from several different years reports.

You can see that the 1990-1991 recession caused actuals to diverge from the 1985 projection (green line). Employment was very slow to recover, taking about 5 years to return to pre-recession growth rates. By 1995 the projection assumed that the low growth rates had a permanent effect. Five years of growth brought things back up, but the 2001 recession turned it down again. Even with the slow recovery from 2002 to 2006, the 5-10 year projection from 2000 was beginning to look too pessimistic.