The approach of March 31. Photographer: Joe Raedle/Getty Images
The approach of March 31. Photographer: Joe Raedle/Getty Images

Hey, reporters! If you’re planning to say anything about the Affordable Care Act's upcoming March 31 numbers, please, please, please read Drew Altman today for an important correction of two mistakes you may be about to make.

First, the total number of exchanges sign-ups: As Altman reminds us, the much ballyhooed 7 million number, adjusted to 6 million after the botched rollout, is a Congressional Budget Office estimate. Not an administration goal. Not what’s needed to make the exchanges work. Not a number that tells us what happens to premiums next year. The only thing one might be able to conclude from whether enrollments top that number or fall short of it would be the effect on the federal budget, which is interesting, but not what we really want to know in terms of ACA success or failure.

Second, the percentage of young people: What the ACA needs are healthy people, not young people. Yes, “young” may be a best available proxy for “healthy,” but it’s really just a guess. If everyone under 30 with awful diseases signs up (or even, I suppose, all the perfectly healthy under-30s who plan to get pregnant in the next year), it’s not helping; if lots of very healthy 40- and 50-year-olds sign up, insurance companies will be quite happy. No one knows what we’re getting; the exchanges don’t ask for health information. So there’s just an enormous amount of guesswork at best.

For both of those factors, it’s important to remember that each state exchange is independent of the others, and each one needs enough people and enough healthy people to ultimately work. It’s also important to recognize that there are built-in mechanisms for the first few years to prevent exchanges from collapsing if they start slowly. And as for next year’s premiums, it’s not just what happens in this year’s enrollments that matters; it’s what happens this year compared with previous estimates by insurance companies, along with what those insurance companies project for next year based on what they know now. That’s one of the reasons why falling short of original projections isn’t all that important as long as insurance companies believe it was linked to the (temporary, one-time) disastrous rollout.

Remember: No one expected everyone to sign up this year, and insurance companies probably made, and will continue to make, very cautious estimates for what will happen, because after all they want this to work.

I’ll give the last word to Altman:

The problem is that it will take time to learn if the mix of enrollees is healthier or sicker, and how premium increases vary around the country, and how people feel about their coverage. Meanwhile Republican politicians will lambast the law and Democratic ones will offer lukewarm support and overall popularity of the ACA probably won’t change very much. Anybody willing to wait for a judgment based on the right metrics?

To contact the writer of this article: Jonathan Bernstein at jbernstein62@bloomberg.net.

To contact the editor responsible for this article: Zara Kessler at zkessler@bloomberg.net.