Greg Mankiw is a great economist, but he often makes really shallow passive-agressive posts over on his blog. In his latest post by the same title, he submits without comment this graph showing a selective nine-year period of the employment-population ratio:
The passive argument here. I assume, is that Obama has failed to produce a recovery in the labor market. Let me be equally passive aggressive and submit a graph of a different nine-year period  of this same series, covering a different "So-Called Recovery":