The WSJ says that Obama hasn't defined it either. It also isn't clear what the cited study in the blog post says, though the title ("Productivity Differences ac

The WSJ says that Obama hasn't defined it either. It also isn't clear what the cited study in the blog post says, though the title ("Productivity Differences across Employers: The Roles of Employer Size, Age, and Human Capital") of the paper does suggest it is for all startups. Link in case someone is an AEA member (to get through the paywall): http://econpapers.repec.org/article/aeaaecrev/v_3A89_3Ay_3A1999_3Ai_3A2_3Ap_3A94-98.htm http://econpapers.repec.org/article/aeaaecrev/v_3A89_3Ay_3A1...