What does the testimony of a Presidential nominee to a nonpolitical federal statistical agency tell you about the strategic approach of the Obama administration? If you observe how it fits a pattern, it tells you quite a bit.
Robert M. Groves is President Obama's pick to head the Census Bureau. From a purely technical standpoint, he could hardly have picked a more qualified candidate to head the bureau. Groves is among the most respected survey researchers in the field. In that sense, the pick resembles the choice of Nobel Laureate Steven Chu as Energy Secretary: each is a highly respected scientist and neither has discernible political leanings.
But an 800 pound gorilla loomed over any pick to head the Census Bureau: whether to use statistical estimation to adjust the results of the Census for purposes of congressional apportionment. The issue is a political hot potato: any hint of using estimation for apportionment would result in screams from the Republican side of the aisle that the Census was being manipulated for political purposes.
Why? While the Census attempts to interview everyone, complete enumeration is an especially imperfect business. And the professionals at the Census Bureau not only know this, they know the characteristics of those they miss. Poor people (particularly homeless ones), minorities, and immigrants are those most likely to be missed -- over 4 million of them according to a study of the 2000 census. And these groups tend to be Democrats -- and live in areas with disproportionately more Democrats. So applying statistical estimation would inevitably increase population estimates in Democratic areas, and thus result in more Democrats in Congress.
Which is more accurate, imperfect enumeration or statistical estimation? There is really no scientific dispute here. The Census conducts hundreds of surveys and produces tens of thousands of population estimates. The Census uses estimation, to my knowledge, for every one of these estimates -- except for congressional reapportionment. The users of the Census want the most accurate data possible. The apolitical scientists know what is accurate and how to derive accurate estimates, and that is achieved through the application of carefully derived and tested estimation models rather than a highly flawed actual headcount with known and systematic errors.
(If you need a non-statistician's explanation of why sampling and estimation is as accurate as an actual enumeration, consider your last blood test: did they remove and test ALL your blood?). These matters are beyond any scientific dispute. Yes, sampling is theory -- the same way gravity is theory.
Groves is a professional sampling statistician. He knows all of this from a lifetime of work in this and related arcane methodological matters. If a purely scientific panel of the most eminent sampling statisticians in the country were commissioned to make recommendations in this area, Groves name would be on the top of almost any list of preeminent experts in this area. Indeed, while serving as Assistant Director of the Census after the 1990 Census, he recommended using sampling and estimation to correct for the known errors in that Census. While from a scientific perspective the issue is a complete no-brainer, Republicans in the Senate have seized on this to assert that he has a partisan agenda.
They clearly do not know the man. I do. I have known Bob Groves for over 30 years as a professional colleague. I have read his work, and even collaborated with him on a couple of papers on some of the specialized methodological issues of survey research that have been his life's work.
And after 30 years of professional acquaintance, I can tell you that I have not a clue about Bob's political leanings. (And those who know me for the political junkie that I am will find this astounding, for the political realm has always been my personal passion: it tends to be among the first topics I gravitate to in any casual conversation). This fact, I think, attests to Bob's nonpolitical nature. He is not motivated politically, he is a Scientist, and one of the first order.
But, curiously, Groves, in his confirmation hearings, indicated that he had no intention to employ or advocate the use of sampling or estimation in conducting the 2010 Census. What gives?
I think this says something very revealing, but far more about the Obama administration than about Bob Groves. I have no doubt whatsoever what Bob's private counsel would be if asked about whether applying estimation principles to the Census would increase its accuracy. Indeed, his scientific judgment on this matter is already a matter of public record. But what is interesting here is how this new position mirrors the Obama administration's approach to dealing with many controversial matters. There is a pattern: President Obama does not want the political distraction of Republicans screaming that the Democrats have "fixed" the Census to produce a partisan result. It would not matter that as a matter of scientific certainty, such claims would be wrong; they could score political points in making the charge. (This is the type of technical issue that is difficult to explain to a statistically lay audience; many intelligent people simply won't understand it.) Obama looks willing to forgo the congressional seats, perhaps a dozen or so, Democrats would gain in order to avoid this political distraction and pursue higher priorities. He has bigger fish to fry.
This strategic retreat resembles the back-burnering of issues such as gun control and gays in the military. Each has been delayed out of a fear that it could be divisive and derail his core agenda, especially the economy and health care reform. To pursue key objectives, he has been willing to delay action on other issues that could distract or dilute his mandate. While he has pursued many initiatives, he has carefully avoided those with the explosive potential to blow up the broader agenda. And an attempt to use estimation for reapportionment has that potential. While the scientific merits are indisputable, getting the public to understand such arcane statistical principles is a lost cause. The Obama administration has concluded that it is simply not worth the political capital to try.
One need look no further than the impact the gays in the military issue had on the early Clinton administration to see the risks he seeks to avoid. The strategy does not necessarily mean that such issues will be avoided indefinitely. But it does argue that they should be held back lest they come to define his Presidency. And, in the case of gays in the military, it allows time for proposals to percolate up from the military establishment rather than appearing to be imposed on them.
A strategic retreat on the matter of employing estimation in the Census is thus one illustration of a selective approach the Obama administration has taken to many issues. Choose your battles carefully, prioritize, and do not give the opposition the opportunity to define you.