The Trump Effect on enrollment

The Journal of Health Politics, Policy and Law (JHPPL) just published my first peer-reviewed original research article. I worked with Dr. Paul Shafer on this article as he had requested and received through Freedom of Information Act (FOIA) week by week county level application counts for 2014-2017.

We asked a simple question that Balloon-Juice readers already sort of knew:

What happened to ACA enrollment during the 2017 Open Enrollment Period when the messaging and implementation regime switched from being very supportive to very opposed?

There had been several analysis that suggested a 4% to 5% decline in total open enrollment. The problem with these analysis is that the counterfactual (2017 trend would have looked like 2016 if the Obama HHS had run the entire open enrollment) was lightly tested.

We ran a descriptive analysis that basically was a repeat of the previous analysis. It suggested that something big happened.

We then ran two, more rigorous models. The first was a difference in difference design which found that the last two weeks of the 2017 Open Enrollment Period had a 30% reduction in applications for insurance. An event study design found a 24% reduction in applications in the last two weeks of 2017 compared to the pre-inauguration trend.

So what does this mean?

Folks who know that they are likely to incur a $100,000 or more in claims are very likely to sign up for health insurance that is community rated, guarantee issued and heavily subsidized no matter what the messaging regime is. It is highly salient and highly important that they get their healthcare covered. They will crawl through glass for coverage. We can also assume (but did not prove as our data was not that granular) that the vast majority of this population had signed up during the time period the Obama administration ran as the coverage that could be bought in the last two weeks of the Open Enrollment Period did not start until March 1st. I think it is reasonable to assume that folks who know that they have a $100,000 claim year would want coverage that started on January 1st instead of running naked to save a few thousand dollars in premiums while spending $10,000 or more in medical expenses.

However, folks who think it is likely that they will be in the bottom 50% of the US healthcare spending distribution ($0-$1,000 in total spend) tend to enroll late. They are the ones who need strong encouragement to go onto the Exchanges and buy. This cohort is where the drop-off is likely to have happened. And once they are not in the 2017 pool, they can’t auto-enroll for 2018 or benefit from Silver Loading as it is unlikely in a low outreach/negative messaging environment that they would have the same probability of looking at the Exchanges for 2018 as unenrolled individuals than if they had been enrolled in January 2017. This is a continual drop in enrollment over several years.

Messaging matters, operationalization matters, but we can’t say a ton more. We can’t say if the executive order drove X percentage of the drop, or if the cancellation of advertising was all of the drop and then some more, or if the general elite political messaging that Obamacare sucked and it would be replaced with something better real soon now did anything. We have hints of a story in the data but nothing strong enough to write on. Further research is needed on these factors (and I’m on a great team doing some of that work) but messaging and political support matters for enrollment in public programs.

21 replies
  1. 1
    stinger says:

    Congratulations, David!

  2. 2
    Another Scott says:

    Excellent. Keep it up. Your h-index will be above 30 before you know it!

    Thanks for keeping us in the loop.


  3. 3
    Ohio Mom says:

    What a great milestone for you — indeed, it’s a Big F-ing Deal!

    This research *will* be used — not right now, obviously, but I dunno, in about three years? — to bolster the case for spending more on promotion and outreach. You may never see the sort concrete evidence you could publish but your efforts will certainly lead to better health for many and extended, saved lives.

    Thank you for starting my day off with good news.

  4. 4
    Chris Johnson says:

    They will crawl through glass for coverage

    They will crawl through glass for health care.

    Sorry for the Cole-like attitude. I think a drop-off in ‘enrollment’ can fairly be attributed to people figuring out it is the insurance industry’s job to deny care and maximize profit. It is supposed to be balanced by very libertarian attitudes that market pressure and the enlightened consumer will prevent companies from exploiting the situation too hard. I don’t believe that is practical.

  5. 5

    @Chris Johnson: that is not what the evidence suggests especially when you examine the differential enrollment between state based exchanges and HC.Gov

    Here are two pieces where I’ve looked into that a bit — We used California as an example of what happens when outreach and promotion is maintained at a high level vs. significantly reduced on

    And here I show State Based Marketplaces responded to CSR termination in the least enrollment damaging ways at a disproproportionately higher rate than states.

  6. 6
    Brachiator says:


    Very cool news.

  7. 7
    J R in WV says:



    Very cool news.

    What he said !!! Carry on!

  8. 8
    Sloane Ranger says:

    @J R in WV: Thirded!

    What a great day for you (less so for those caught out by not buying insurance

  9. 9
    Mary G says:

    Congrats to you!

  10. 10
    Gin & Tonic says:

    @Another Scott: But what’s his Erdős number?

  11. 11
    FelonyGovt says:

    Congratulations and thank you for doing such important work. It will certainly be used by a more enlightened Administration.

  12. 12
    ML says:

    Would it make sense/be possible for some deep-pocketed Dem donor to sponsor ads nationwide in the last two weeks of enrollment to make up for lack of govt advertising? (eg, Tom Steyer, but for Obamacare enrollment rather than impeachment. Another option, Marc Benioff, who’s already a huge benefactor of hospitals and medical research.)

  13. 13
    dnfree says:

    We can say we knew him back when he was Dick Mayhew! So glad to see your talents recognized and put to use.

  14. 14
  15. 15
    Epicurus says:

    I think the one big takeaway is that Donald Trump is a lying sack of crap, who will tell his followers any lie, make any exaggeration to aggrandize himself and his own “accomplishments.”

  16. 16
    MomSense says:


  17. 17
    Mai Naem mobile says:

    No doubt the opposition from this administration didnt help but isnt it possible that the improving economy and lower unemployment rates contributed a little to the decreased applications.

  18. 18
    Miss Bianca says:

    Excellent work (as always), David! Congratulations!

  19. 19

    @Mai Naem mobile: Not in the last two weeks of January 2017. The economy was a near constant from November 1, 2016-January 31, 2017 and the pre-inaguaration trends showed that enrollment for 2017 was running at to slightly ahead of the 2016 pace.

    Going forward, yeah, a better economy, all else being equal should put some downward pressure on ACA enrollment if we assume new jobs are good enough to come with benefits and/or the labor market is tight enough that jobs that previously did not offer insurance now offers something. I think that is a reasonable take (not sure of the size of the sign but it is non-zero)

    We should also factor in more Medicaid expansion mechanically takes people out of the ACA pool (Louisiana was excluded from this paper as they expanded Medicaid mid-summer 2016)

  20. 20
    Another Scott says:


    Donald Trump opened his presidency in January 2017 with a series of salvos aimed at the Affordable Care Act, the signal achievement of his predecessor’s administration.

    It has long been assumed that these attacks reduced signups during the crucial final weeks of open enrollment for 2018 insurance policies. New data parsed by two experts at Duke University and the University of North Carolina show how steep the reduction was. Spoiler: It was huge, and devastating.

    That’s because the drop-off was concentrated among the healthiest group of potential enrollees. They’re the ones who often wait until the last minute to sign up, and therefore were still pondering their options on Inauguration Day, Jan. 20, and up to the enrollment deadline of Jan. 31.


    Hey, what every happened to that Mayhew fellow that used to cover stuff like this here?!?!


  21. 21
    Another Scott says:

    This paper is being noticed by at least some people in Congress. Rep. Don Beyer.

    Keep it up!


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