“Earlier today, Marilyn Tavenner of the Centers for Medicare and Medicaid Services announced that “more than 6 million Americans have signed up for coverage through the Health Insurance Marketplaces since October 1, thanks to the Affordable Care Act.” Given all of the technical problems that dogged healthcare.gov last October, this is an impressive turnaround. But it sheds little light onto the two questions most analysts are focused on. First, how many of those signing up have paid their first month’s premium, thereby activating coverage? And second: How many of those with coverage were previously uninsured? At this point, we have no definitive answers.”