There’s just over a week left to enroll in Obamacare for next year and, so far, enrollment on the federal exchange is down sharply compared to last year. From the Hill:

In the first five weeks of this year’s sign up period, about 3.2 million people have signed up for ObamaCare plans, compared to the 3.6 million who had signed up by this point last year.

That’s a decrease of more than 406,000, or 11 percent.

In week five alone, which ran from Nov. 25 through Dec. 1, 773,000 people signed up for ObamaCare plans. In week five of last year’s sign up period, 823,000 people signed up for coverage.

There are a few caveats here. For one, the cumulative totals have one fewer day of signups this year than last year because the opening week was one day shorter this year. That could account for at least some of the cumulative difference compared to last year. The other big caveat is that enrollment in the program always peaks in the final week, so it’s still entirely possible some of that deficit will be made up for by a last-minute surge. However, the NY Times quotes one observer who says it’s unlikely the results will top last year’s numbers:

Several experts believe that the slow start in enrollment this year is likely to mean a smaller Obamacare market for 2019.

“Based on what we know now I would be shocked if enrollment was higher this year than last year,” said Josh Peck, a co-founder of the group Get America Covered and the former chief managing officer for Healthcare.gov during the Obama administration.

As for why this is happening, there are a few obvious explanations. The most obvious of these is that the individual mandate no longer applies this year, which means there is no penalty for refusing to purchase insurance which, for those not receiving subsidies, is expensive. However, Chris Sloan of Avalere Health tells CNBC he doesn’t think the mandate will make that big a difference because even when it was in place it wasn’t that hard to get out of it by claiming some sort of exemption.

Another factor is that the Trump administration cleared the way for new plans which offer less comprehensive coverage but are much cheaper on a monthly basis. Some people who choose not to purchase Obamacare could be opting for the new plans instead. Finally, it’s possible that the improved economy might be playing a role. From CNBC:

The tight labor market is helping reduce dependence on the federal program, said Joel Cantor, the founding director of the Center for State Health Policy at Rutgers University in New Jersey.

“The economy has increased employment rates and encouraged more firms to offer decent benefits in order to be competitive in labor markets,” he said.

While the ACA law doesn’t require small businesses to offer health coverage, more may now being doing so to attract and retain workers, he said.

Charles Gaba at ACASignups is an ACA supporter but his predictions have been pretty accurate in the past. Today he has a blog post looking at the new government numbers plus the numbers for most of the states not using the federal exchange. He projects that final enrollment numbers are going to be down this year but not by double digits:

For the state-based exchanges, California is also running slightly behind. DC behind as well, but only includes 2 weeks of data so that could have changed by now. Overall, however, the state-based exchanges are running around 1.7% ahead of last fall (no idea what’s up in ID, MD or VT, of course). Keep in mind that most of the state exchanges include auto-renewals, while HC.gov doesn’t.

Nationally, missing data/states notwithstanding, OE6 is running around 6.4% behind last year so far. I still expect the final total to end up around 4.9% behind.

We should have a much better idea if he’s right in a couple weeks when the final cumulative numbers from federal exchange numbers are released. However, some states including California don’t close enrollment until January, so we won’t have a really accurate final tally for about two more months.