Michael Tanner of the Cato Institute has been monitoring the Obama administration’s Obamacare enrollment “victory tour.” He explains in his latest National Review Online column why he’s not ready to join the celebration.

Given the debacles of healthcare.gov and the initial rollout of the health-care exchanges, the fact that slightly more than 8 million Americans have signed up for exchange-based plans is a significant accomplishment. In addition, a few million more Americans have enrolled in Medicaid, and some more young people were able to remain on their parents’ insurance policies. Certainly, things could have been worse.

But if this is victory, I’d hate to see defeat.

Let’s start with that 8 million figure.

Republicans were a bit premature last week when they jumped on the House Energy and Commerce Committee’s report stating that more than a third of enrollees had not paid their first month’s premium. That number was skewed by the surge of late enrollees, many of whom had not even received their first bill and so obviously hadn’t paid. However, the administration can’t be let entirely off the hook, since it has steadfastly refused to provide any information on actual payment rates. Its insistence that insurance companies won’t provide it with those data is risible. On the basis of earlier numbers, it seems likely that 15 to 20 percent of those signing up will never pay, and perhaps 3 to 5 percent will ultimately stop paying and drop their coverage.

Moreover, we still don’t know how many of those signing up through the exchanges were previously uninsured, as opposed to people voluntarily or involuntarily switching plans. We do know that as many as 6 million Americans lost their coverage because it was not compliant with Obamacare’s many mandates, and that perhaps 1 million of those remain uninsured. How many of the rest bought new coverage through an exchange remains murky, though some estimates suggest that the majority of these people found new insurance through the exchanges or Medicaid, or from an employer. …

… Putting it all together, and including those on Medicaid and those remaining on their parents’ policies, the administration may have succeeded in covering 20 percent of the 48 million uninsured Americans. That’s not much to cheer about.

In addition, the Congressional Budget Office projects that for Obamacare to reach its intended targets, exchange enrollment will have to more than triple by 2016. This seems like a pretty tall order. And even this would cover only about half the uninsured.