[WS:] That crossed my mind too. I wonder to what degree the new "hires" are in fact insider promotions, which appear as "hiring those who already have jobs." I've seen that quite a bit in the academia and government - they advertise a position because legally they have to go through the motions, but they already picked their candidate - often from within the organization.
Another aspect is that "networking" in getting these kinds of jobs is crucial, and people who are employed typically have better networking opportunities than those who have been out of a job for a while.
Wojtek