Harvard economics chair Greg Mankiw has decided to repeat incorrect right-wing talking points that defy common sense. Yesterday he posted (and this is the entire post, not an excerpt):
John Lott points out the following: “So far this year there have been 848,000 new jobs. Of those, 813,000 are part time jobs…. To put it differently, an incredible 96% of the jobs added this year were part-time jobs.”
That’s astonishingly bad. It’s also very incorrect. From the perspective of being misleading, perhaps most important is the failure to distinguish between part-time jobs worked for economic reasons (which the Bureau of Labor Statistics (BLS) defines as: slack work or business conditions, could only find part-time work, seasonal work, job started or ended during week) and non-economic reasons (defined as child care, family obligations, health problems, being a student, and a few others). Looking at Lott’s own data, since January, there are 62,000 fewer part-time workers who are stuck in part-time jobs for economic reasons. The growth in part-time jobs has taken place entirely for non-economic reasons.
Even setting aside the distinction between voluntary (non-economic) and involuntary (economic) part-time work, Lott still has two big methodogical problems. First, the time-frame he uses is not nuetral, and second Lott combines the data series in a way that BLS did not intend. To be fair, Lott does update his post to note that using correct BLS data, just under 2/3rds of new jobs from Jan 2013-Aug 2013 are part-time. This is still really high, but not the eye-popping 96% he initially claims and Mankiw repeats. But it also turns out that the first eight months of the year aren’t really a neutral time-frame, as January was a low-point for part-time workers. Going the full year from August 2012-August 2013 I find 1.716 million more full-time jobs and 288,000 additional part-time jobs. That makes part-time jobs 14.4% of new jobs over the last year. Now, if there’s a reason to think that the overall economy changed drastically in January then there’d be a case for throwing out the August-August comparison in favor of the shorter time frame. But I don’t see one. Using the same Bureau of Labor Statistics data that Lott is, here’s a graph of last year’s part-time and full-time jobs:
The big trend that sticks out is that they’re both flat. The economy is not doing well. But part-time jobs aren’t exactly surging. They did during the recession, and it is a problem that they haven’t come back down. Here’s a longer view of part-time jobs as a percentage of total jobs from the Federal Reserve (note: you want to look at the red line that adjust the data for a change in CPS surveying methods made in 1994):
Again, a huge spike during the recession, but not in 2013. The point here is not to try to paint a rosy picture of the economy. The point is that an economics professor at Harvard ought to know enough not to repeat statistics that seem too extreme to be credible, and come from a disreputable source, without first doing a little checking on his own.