WASHINGTON — You can say one thing about the Affordable Care Act enrollment figures the Obama administration released this past weekend: They’re a lot better than October’s.

The administration says that 1.1 million people enrolled through Healthcare.gov by the December deadline. If you add that to preliminary data from the states, almost 2 million people seem to have signed up for health care through the exchanges, plus several million in Medicaid.

Is that good, or bad?

It’s good if you compare it with what happened in November, or to an alternate scenario in which the website ran so badly that no one could really sign up by the deadline.

It’s bad if you compare it with the administration’s internal projections, which had about 3.3 million people signed up by now. They’re about 40 percent under that target.

But how bad? We don’t really know, because questions remain:

• Will millions of enrollees show up later than expected? The uninsured could be planning to wait until the last possible moment to buy, in order to save a little money. The administration’s projections weren’t delivered by infallible prophets; they were guesses about something that has never happened before.

• What will the demographic mix look like?

Low enrollment is a problem in itself, because small insurance pools are inherently unstable – a few extra bad events can push your insurer deep into the red if they’re covering only a small number of patients. But this problem isn’t insurmountable, and Obamacare has some temporary stabilization measures built in that should alleviate these issues for the first few years.

Those measures, however, were designed to protect against a few insurers who got unlucky – not against having a whole market composed of people who are older and sicker than expected. The real danger of low enrollment is that the people who are missing will disproportionately be younger and healthier folks who were expected to pay premiums without using a lot of services.

• How many will pay? Jon Kingsdale, who oversaw the implementation of the Massachusetts exchange from 2006 to 2010, wrote in November that “Tracking billing and collections was a much bigger challenge than getting our Web site to work.”

Some people will never pay their first month’s premium; others will stop paying quickly thereafter. We won’t really know how many gained insurance through the exchanges for a year or so.

• How many of the people buying insurance on the exchanges already had insurance?

To state the obvious, few people would have supported a radical overhaul of the individual insurance market if they had thought most of the people who bought insurance through the new exchanges would be folks who already had insurance. Perhaps we’d have done a Medicaid expansion, but not a re-do of the private insurance market.

We don’t know yet whether most of the 2 million enrollees were already insured, or represent uninsured people who got new insurance, and probably won’t for a while. Which brings me to the next thing we need to know:

• How many people who lost insurance thanks to Obamacare mandates renewed policies outside of the exchanges, or obtained insurance elsewhere? Two million is a high number compared with the figures for October and November.

But it is a low number compared with the number of people who lost their individual market policies because those policies weren’t in compliance. And we would have expected all of those people – estimated to be somewhere in the range of 5 million – to buy new policies by the end of December. So did they get insurance directly through their insurer, or perhaps go on a spouse’s employer policy? Or did they drop insurance entirely?

• These last two categories have special bearing on the big long-term question: Is Obamacare now beyond repeal? Has it garnered enough enrollees that it will be politically impossible to get rid of?

Of course, there’s no magic number that constitutes a line beyond which the law’s opponents dare not cross. Besides, this year’s numbers could go up, or down, next year. And the law is undoubtedly going to change in the near future, in ways that will make it more or less stable than it is now.

The best we can say now is “not dead yet.” And that in itself is some improvement from the dark days of October.

— The Washington Post News Service with Bloomberg News