In short: young firms.
As the following chart summarizing OECD data for the developed world, all the net job creation in the 21st century has come from firms that are 5 years old or less, having even created jobs during the peak years of the post-Lehman depression. And where do jobs go to die? Simple - old corporations, as firms older than 6 years having been net eliminators of jobs since the year 2001!
What is perhaps paradoxical about this data, is that as we have shown in the past, the one age group that has benefited the most in the US "New Normal" are old workers, those 55 and above, who have been the net recipients of all job creation since the onset of the second great depression (and whose employment level just hit all time records). As for workers under 55, i.e. those in their prime, they still have several million jobs to recover before they get back to even.
The conclusion? In order to spur a true recovery, and not one of the S&P500 price level, where corporations give the impression of normalcy as a result of corporate buybacks and QE of course, governments of the developed world should encourage creation of new firms. Instead what do they do? Allow themselves to be manipulated and pander to the well-established D.C. lobbies of the decrepit corporate cryptkeepers that control all the levers... and continue to fire in droves.