A Few Questions About Obamacare and the Uninsured Rate

The good news for Obamacare supporters is that a monthly tracking poll from Gallup finds that the percentage of uninsured Americans dropped this month, the first in which Obamacare's major coverage provisions kicked in. The uninsured rate dropped from 17.3 percent down to 16.1 percent between December of 2013 and January of this year, according to the Gallup-Healthways Well-Being Index.  

The less-good news for the health law's backers is that the uninsurance rate is still essentially the same as it was in the early months of 2010, when the law passed. And it's still several points higher than it was late in 2008, just as the recession hit, and when President Obama finishing his first campaign.

Here's the graph:

The survey results leave a few unanswered questions:

How much of this month's result is just normal variation? There have been numerous large month-over-month spikes and drops in the numbers over the years, and this month's dip isn't far out of the normal range. While it's unlikely that normal variation explains the entirety of this month's drop, it may explain some or even most of it. 

What happened during the summer of 2013? The uninsured rate jumps all the way up to 18.6 percent, almost a point higher than its previous high, before it starts falling again in the second half of the year. 

How much of the expansion of insurance comes from Medicaid, and how much is in private insurance? The report doesn't attempt to break out the number of people who are insured through Medicaid, the federal-state program for the poor that was expanded under Obamacare. And federal data on Medicaid enrollments since October of last year isn't very helpful either, since it doesn't differentiate between people who renewed prior Medicaid coverage and people who are newly covered under the health law. But it would be interesting to know. In theory, it's still possible that the number of people with insurance of any kind (including Medicaid) has increased, but the number of people with private insurance has not.