The jobless rate fell sharply again — from 7.0 percent to 6.7 percent — but the reason wasn’t a burst of new job creation. In fact, total employment was up by just 74,000. What changed in December was that new layoffs fell sharply, which we usually see in the first two years of an expansion. It’s some two years behind schedule, but the number of newly unemployed people was down by 365,000 in December. The rest of it was mainly demographics, not economics. Yes, the labor participation rate fell 0.2 percentage points — but it had risen by as much the month before. Moreover, the number of “discouraged workers” (those no longer looking for work) and those “marginally attached” to the labor force (who haven’t tried to get hired for a month) did not go up. What continues to rise are the numbers of baby boomers retiring, because the numbers of boomers reaching ages 60, 62 or 65 continues to accelerate.