Small businesses are basically saving the job market right now by Benjamin Snyder @FortuneMagazine February 27, 2015, 11:53 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons There’s been a surge in post-recession small business hiring across the country, according to a new report from ADP Research Institute. Companies with 499 employees or less accounted for 81% of new private-sector positions in January, ADP says. Expand out the time frame, and small businesses averaged 83% of new jobs in the last four months. For comparison’s sake, small businesses were only responsible for 38% of new private-sector jobs back in September 2010. What explains the small business hiring boom? Jim O’Sullivan, chief U.S. economist at High Frequency Economics, told Bloomberg that startups have been benefitting from easier access to capital. “In general, small businesses were hurt more by the credit crunch than big firms and that headwind for the recovery has become a tailwind as the banking sector has strengthened and eased lending standards,” O’Sullivan told Bloomberg. The recent small business blitz comes as startup owners reported their highest optimism levels in eight years last month.