Well, they may look fishy, but here's the story from the WSJ:
Originally Posted by j-mac
[...]The employment gain wasn’t immediately obvious to some observers because of a quirk in this month’s report. Every January, the Labor Department readjusts its data to account for changes in the population. The tweaks are especially significant in years like this one that take into account a new decennial census.
This year, the population adjustment makes it look like the employment-population ratio didn’t change from December to January. In reality, the ratio improved by 0.3 percentage points. The gains were just masked by the population adjustments.
Here’s what happened: According to the Census Bureau, the civilian population grew by 1.5 million people in 2011. But the growth wasn’t distributed evenly. Most of the growth came among people 55 and older and, to a lesser degree, by people 16-24 years old.
Both groups are less likely to work than people in their mid-20s to early 50s. So the share of the population that’s working is actually lower than previously believed. Taking that into account, the employment-population ratio went up. The unemployment rate wasn’t affected.
“There was not a big increase in discouraged workers,” economist Betsey Stevenson commented on Twitter. “What happened was Census found a bunch of old people we had assumed died.”
What’s Behind the Unemployment Rate Drop? - Real Time Economics - WSJ