…will make it hard to evaluate the effect of Obamacare.

How very convenient:

The Census Bureau, the authoritative source of health insurance data for more than three decades, is changing its annual survey so thoroughly that it will be difficult to measure the effects of President Obama’s health care law in the next report, due this fall, census officials said.

The changes are intended to improve the accuracy of the survey, being conducted this month in interviews with tens of thousands of households around the country. But the new questions are so different that the findings will not be comparable, the officials said.

An internal Census Bureau document said that the new questionnaire included a “total revision to health insurance questions” and, in a test last year, produced lower estimates of the uninsured. Thus, officials said, it will be difficult to say how much of any change is attributable to the Affordable Care Act and how much to the use of a new survey instrument.

“We are expecting much lower numbers just because of the questions and how they are asked,” said Brett J. O’Hara, chief of the health statistics branch at the Census Bureau.

It’s worth reading the whole article, which sheds light on how the questions used to be asked versus how they will be asked in the future. The gist of it is that the older method encouraged overestimate of the number of uninsured, while the newer method will be more accurate. That is, the older method bolstered the liberal argument that way too many people were uninsured and that we desperately needed health insurance reform of a major sort to rectify the problems, whereas the new method will tend to yield figures that would support the idea that Obamacare has been very successful in reducing the ranks of the uninsured, which can be used (and no doubt will be used) to justify the passage of the ACA.

Kind of neat, isn’t it? And a complete coincidence, of course:

Another Census Bureau paper said “it is coincidental and unfortunate timing” that the survey was overhauled just before major provisions of the health care law took effect. “Ideally,” it said, “the redesign would have had at least a few years to gather base line and trend data.”

But I guess they had no control over that. And yes, I’m being very sarcastic—although come to think of it, knowing the ponderous way government and its agencies work, it’s actually possible they didn’t.