British Prime Minister Benjamin Disraeli is credited with the statement famously repeated by Mark Twain: "There are three kinds of lies: lies, damned lies, and statistics."

Expect this general sentiment to be debated quite a bit for the next few weeks. On Monday, the Congressional Budget Office (CBO) announced its projection that 22 million more Americans will be uninsured by 2026 under the Better Care Act (already being referred to as Trumpcare) than would be the case under current law. The sparks began to fly immediately.

Back in 2012 after the Supreme Court upheld Obamacare but allowed states to choose whether or not they would expand Medicaid, the CBO projected that Obamacare would result in 23 million to 25 million more Americans gaining health insurance through the state exchanges. The actual totals for last year were 12.7 million. Could the CBO's Trumpcare estimates be just as far off? 

Man calculating numbers

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Just how bad were those Obamacare projections?

At first glance, the CBO's estimate for Obamacare being off by over 10 million looks pretty bad. Heck, it even looks bad at second glance. After all, that's an error margin of roughly 45%. With that kind of accuracy, Trumpcare could result in 32 million additional Americans without insurance by 2026 -- or perhaps only 12 million more. 

There is more to the story, though. In 2012, the CBO projected that by 2016 10 million to 11 million additional people would be enrolled in Medicaid as a result of Obamacare. The actual increased number of Medicaid members in 2016 was 14.4 million.

So the CBO overestimated the number of people gaining insurance through the exchanges and underestimated the number who would be added through Medicaid. Factcheck.org says that "to a large extent, CBO's mistake was in estimating where the uninsured would get covered, not how many of them would gain coverage." But did Factcheck get their facts right?

Simply comparing the degree to which the CBO's Obamacare projections were off shows that the underestimation of Medicaid enrollment by 4.4 million doesn't come close to offsetting the overestimation of exchange enrollment by 10 million. And those comparisons are being generous to the CBO by using the low ends of both projected ranges for Obamacare.

More important, though, is that the 14.4 million increase in Medicaid enrollment didn't come solely as a result of Obamacare. According to the nonpartisan Kaiser Family Foundation, almost 3.3 million of that figure included individuals who would have been added to the Medicaid rolls without Obamacare.

That means the actual increased number of Medicaid members in 2016 due to Obamacare totaled around 11.2 million. The CBO underestimated the Medicaid enrollment increase from Obamacare, but only by a relatively small amount. 

It's not easy being Nostradamus

I don't think anyone should take potshots at the CBO, though -- it has an extraordinarily tough job. It's asked by Congress to make projections that require it to predict how people will react to a new regulatory environment. That doesn't just involve statistics -- it essentially requires fortune-telling. 

Here's what the CBO itself said about the Trumpcare estimates: "[These] estimates are inherently inexact because the ways in which federal agencies, states, insurers, employers, individuals, doctors, hospitals, and other affected parties would respond to the changes made by this legislation are all difficult to predict. In particular, predicting the overall effects of the myriad ways that states could implement waivers is especially difficult."

The CBO also acknowledged that its projections about Obamacare could still be off. If Obamacare doesn't increase the number of Americans with health insurance by the latest projections, that could reduce the 22 million gap that the CBO is currently estimating for the Senate version of Trumpcare. 

Lots of uncertainty

You'll probably hear the 22 million number close to 22 million times between now and the end of the summer. The reality, though, is that we have no idea how close to reality that number will actually be if Trumpcare becomes law. And that's a big question mark, at this point, considering that several GOP senators have said they couldn't support the bill.

However, there are couple of things about Trumpcare that are likely to happen if it is passed. First, it would probably mean that millions more Americans would be uninsured than would be under Obamacare, since the financial assistance for buying insurance would be reduced and the penalties for going without health insurance would go away. Second, it would probably reduce overall federal healthcare spending by dramatically changing Medicaid funding.

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