My gut says most of them just quit once the bills arrived - you don't sign up for something and then go, oops, hey, I just got a job. I don't need this. Seems more likely they felt the sticker pinch and said "screw this". Remember that early on, there was some concern that many who signed on hadn't paid anything yet. I don't think it's possible that MANY people suddenly got employer-based healthcare and never had it before.
But of course, it doesn't say. I'll have to find another source.
A couple of things:
(1) I think we'll likely get some more clarity, during this coming earnings season, on the issue of how many people never paid their premiums after having signed up for individual coverage through the new health care exchanges. I expect the health coverage providers to be asked about that issue during their conference calls if they don't address it in their quarterly filings, and I think the just ended second quarter is where the effect would have been most significant. Most of the people (i.e. representing those big health coverage providers) that I've seen speak about it so far have downplayed the impact / number of people that never paid. But who knows what the actual numbers are, hopefully we'll get a decent sense soon enough. With these kinds of services - where you sign up for them and only after being accepted for or accepting the policy do you get a bill - there's always going to be a portion of people that never pay and thus never actually get the service. Will that portion be especially high in this context? I don't know, but for various reasons I'd bet it's somewhat higher than what might otherwise be considered typical.
(2) With regard to what is being estimated here by Connect for Health Colorado - the subject of this thread - that's something different. They're estimating the effect of coverage churn over the course of a given year. They're saying, for instance, we expect a total of 200,000 people to be covered by insurance purchased through C4HCO for some part of FY2015. But because of the effect of churn that will equate to, for instance, 150,000 people being covered for a full year. Some of those 200,000 won't be covered at the beginning of the year, they'll add coverage later. Some of them will have coverage at the beginning of the year but then move to getting coverage a different way or not having coverage at all (e.g. because they stopped paying at some point).
As for why people's coverage might change over the course of a year, there are lots of reasons such as those you've referred to. Changes in people's circumstances will make them ineligible for exchange coverage (or ineligible for subsidies) or ineligible for another kind of coverage (such that they then need to get coverage through an exchange). These changes might be based on their employment or income (moving up or down in income will affect eligibility for various forms of coverage) or other circumstances of their lives. Anyway, this isn't about the number of people that never actually have coverage because they never pay their premium, it's about people's coverage changing over the course of the year - it's about how do you account for the average number of people covered (so to speak) over the course of a year as compared to counting the total number of people that are at some point covered.
I'd add that this kind of churn isn't really unexpected. A number of studies conducted in the wake of ObamaCare's passage raised this as a potential problem. Because there are now so many different ways that someone might be covered, and there are a number of moving parts when it comes to where someone might be eligible or otherwise able to get coverage, and a number of things can change someone's eligibility even within the course of a year, there was concern that we'd see very high churn when it comes to where and how people got coverage. That raises a number of issues relating to, e.g., continuity of coverage. How such problems might be mitigated will be interesting to see. It's yet another problematic dynamic that is likely to be exacerbated by ObamaCare.
EDIT: I guess I should link something that gets a little further into the dynamic / concern that I'm referring to.
Here's one such thing from the Urban Institute, if you don't buy what it's selling you can probably do a google search and find other stuff discussing the issue and make your own assessment.