Quality in a Census, Some Overview Thoughts

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Written by: Director Robert Groves

The series of posts on quality of a census all made the point that there are various ways to measure how good a census is – all of them imperfect.

I think it important to note that, in my judgment, the ideal of “count every resident once, and only once, and in the right place” is the correct target. I also must admit that the US Census never has, and likely never will, achieve that goal.

There are inherent limits.

The population of the United States is changing minute to minute. Every hour there are about 490 births in the country and about 280 deaths. Roughly 12.5% of the households move each year (that’s about 1600 per hour), and some people leave the country and others enter the country each hour. In short, the US population never stops changing. The U.S. has chosen April 1, 2010, for the reference date of the census. However, given birth, deaths, and migration, the population was changing throughout the day. Strictly speaking, there is no single right answer of what the population on April 1, 2010 was.

This implies that the reapportionment of the House would theoretically change with such changes. Indeed, taken to the extreme, the reapportionment in December 2010 is based on an April 2010 count that is somewhat out-of-date. The country has changed somewhat between April and December.

Practical compromises are needed. For reapportionment purposes the US Constitution specifies that once every ten years is the appropriate “fixing” of the proportional representation in the House of Representatives. There have been no initiatives to try to make the distribution of House seats based on more timely data.

Countries vary on how timely the census data must be for their purposes. Some, like Canada, are not satisfied with every 10 year data and mount a full census every 5 years.

Perfection is impossible; expectations of quality might come from comparisons across countries. A common method of estimating undercounts is the post-enumeration survey technique we use here as well. (The designs of these are somewhat variable across the countries; estimates are somewhat incomparable.) The undercount in the 2001 UK Census is estimated to be 5.7% of the total population. This compares to 2.8% in Australia’s 2006 Census. The 2006 Canadian Census had an estimated 2.7% net undercount. The undercounts are not necessarily getting lower each census. For example, the 1996 Canadian Census estimated a 2.4% net undercount.

In 1980 we had 12 undercount estimates centering around 1.4%. In 1990 our undercount estimate was 1.6 %. The comparable figure for the 2000 U.S. Census is a 0.5% overcount. The average over the three decades’ censuses is an undercount of about 1%. That sounds small, but on a population of about 310 million, it translates to 3.1 million people.

Those are net figures. Most professionals would agree that the key issue is the “gross” not “net” coverage, separately accounting for those enumerated more than once (double counted) and those not counted at all. We don’t have many comparable estimates from other countries on this matter.

Each country, for each census, with a combination of professional and media commentary makes a judgment about whether the census counts are “good enough” for key uses.

Acceptable results are attained short of perfection. I could find no country that has stated an acceptable target for net undercounts. (I’d be interested if anyone knows of such an example.) Most strive for complete and uniform coverage of the population. Most acknowledge the impossibility of that goal. Most evaluate how close they come to such a goal, as an act of transparency to the society that must use the census figures.

Much attention is paid to the acceptability of efforts to achieve complete and uniform coverage, at the inception of the census, in order to gain acceptance of the final results. Throughout the decades in most countries, even though the weaknesses of censuses have been acknowledged, the societies have used them as the best uniformly available for key purposes.

In that regard, census-taking is not unlike many human endeavors that have nearly unachievable, but deeply valuable goals – eradicating childhood diseases, attaining universal voter registration, or eliminating traffic accidents. All efforts that effectively get us closer to those ideal states merit consideration. Even without achieving the goal, however, continuing our efforts toward the goal is important.

In the end, each of us must make a decision whether each census, having failed perfection, is suitable for our uses. This can best be done if the Census Bureau is completely transparent about its methods.

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12 Responses to Quality in a Census, Some Overview Thoughts

  1. Ex-Census Worker says:

    With due respect I beg to agree with your views but may take this opportunity to differ to some extent.
    Sir,Your contention that undercount for various reasons is evident and it is agreed that no CENSUS CAN BE PERFECT, BUT WITH MODERN TECHNOLOGY AND TRANSPERCENCY WITH THE PRESENT RESOURCES VIZ INTERNET ETC.
    BUT YOU SHALL AGREE THAT UNDERCOUNT IS MOSTLY DUE TO HUMAN FACTORS VIZ IMMIGRATIONS, DIVERSIFY COMMUNITIES AND THEIR REPRESENTATIONS IN THE SOCIETY AND SOME ISSUES REGARDING RELIGION /ETHENCITY /RACE ETC CONTRIBUTES A LOT IN UNDERCOUNT in addition to issues on indiviual cases which with constant follow-up may have been resolved as I feel.
    Without getting into debate ,Sir you shall agree that undercount in other countries is also for above reasons such as issues religion/race /ethncity.
    as major reason for undercount in my opionin.Moreover the subject is so complex that with all out efforts we can reduce the undercount only .
    However in the present circumstances it is strongly felt that to make CENSUS IN FUTURE MORE EFFECTIVE NEEDS REFORMS IN THE PROCESS.
    I am of the opionin if measures to make Census as an independent agency to work all thru and not as every 10 yrs agency in the name and style of DEPRTMENT OF NATIONAL REGISTRY indepentent of immigration status or other issues on religion,race etc as it is being done in U.K. AND SAID DEPARTMENT AS GIVEN TO UNDERSTAND GETTING INVOLVED WITH COMMUNITIES AT GRASS-ROOT LEVEL WITH RESOLVING RACE/ETHANCITY ISSUES TO THE EXTENT POSSIBLE.
    I also feel in the best interest NATIONAL I.D. CONCEPT SHALL BE ULTIMATE AIM FOR ALL CONCERNED WITHOUT IMMIGRATION STATUS i.e. citizen /no citizen/race etc. AS PER MY UNDERSTANDING IT IS BEING TRIED IN INDIA THE CONCEPT OF NATIONAL I.D.
    Your posts have been very informative and fascinating on the subject . In the context based upon the latest post I strongly feel that the issue is of global nature and no nation can do without it for its infrastructure for one reason or other,the subject if deem fit may taken at United Nations level to exchange ,share problems with them and the matter may dealt accordingly in the future.
    I do not know if I am able to express myself to make my views .
    Meanwhile please accept my special thanks for helping us understand the process of census with your posts and has given an opportunity to share our views and may please excuse for any errors and omissions if any.
    With kindest regards,
    Ex-Census worker

  2. M. H. Norman says:

    I received a request to complete a 2010 Census Quality Survey. Due to undergoing treatment for cancer, I did not complete the survey, nor did I send it in.
    This week, I received correspondence from Mr. Groves that said I could complete the survey online at https://respond.census.gov/quality. Wanting to help, I have been trying to access this site, but I have been unable to do so. Google searches have been unable to find the site.
    Please let me know why I am unable to access the site.

  3. Census Enumerator 2008-2009 says:

    Dr. Groves, we in the U.S. must also not be satified with the 10-year plan as well. (Per my direct letter to you in March of this year with pertinent suggestions on how to carry out the interim 5-year plan) Simply request to the legistators to carry it out as an ‘interim’, Constitutional influences notwithstanding. They would value the much more accurate data as it affects the redistricting of voter placements. Ultimately, likewise would the public as they would see the beneficial results of the census much sooner than in the decentennial concept. We can change?!

  4. Census Enumerator 2008-2009 says:

    Dr. Groves, we in the U.S. must also not be satified with the 10-year plan as well. (Per my direct letter to you in March of this year with pertinent suggestions on how to carry out the interim 5-year plan) Simply request to the legistators to carry it out as an ‘interim’, Constitutional influences notwithstanding. They would value the much more accurate data as it affects the redistricting of voter placements. Ultimately, likewise would the public as they would see the beneficial results of the census much sooner than in the decentennial concept. We can change?!

  5. Census Enumerator 2008-2009 says:

    Dr. Groves, we in the U.S. must also not be satified with the 10-year plan as well. (Per my direct letter to you in March of this year with pertinent suggestions on how to carry out the interim 5-year plan) Simply request to the legistators to carry it out as an ‘interim’, Constitutional influences notwithstanding. They would value the much more accurate data as it affects the redistricting of voter placements. Ultimately, likewise would the public as they would see the beneficial results of the census much sooner than in the decentennial concept. We can change?!

  6. Cenus Enumerator 2009-2010 says:

    Dr. Groves, recommend that USCenBur run with an (internet) interim 5 year census to achieve a better accuracy in light of changes happening more quickly than in past decades. The public will see the benefits of census cooperation much more so than with the ‘decennial plan’.

  7. Cenus Enumerator 2009-2010 says:

    Dr. Groves, recommend that USCenBur run with an (internet) interim 5 year census to achieve a better accuracy in light of changes happening more quickly than in past decades. The public will see the benefits of census cooperation much more so than with the ‘decennial plan’.

  8. Cenus Enumerator 2009-2010 says:

    Dr. Groves, recommend that USCenBur run with an (internet) interim 5 year census to achieve a better accuracy in light of changes happening more quickly than in past decades. The public will see the benefits of census cooperation much more so than with the ‘decennial plan’.

  9. One in 1.6M says:

    Some of us may know the saying “The Best is the Enemy of the Good”, a concept which may work in surgery, cooking and woodcrafting (in which tweaking just that one little bit can unravel the overall product), but it can be agreed that setting one’s sights higher than practicable is the means to improvement of anything we do. To ignore reality while doing so is just begging for disappointment.
    Direction at Census is faced with the task of objectively enumerating (in this case) the inhabitants of our Land, but that is complicated by the subjective aspect of people’s freedom not to participate if’n they don’t want to (regardless of the requirement by Law; we all know of those who say they simply won’t). Compound this with issues such as Census’ taking the fallout from the Second War Powers Act (when Census actually attempted to maintain confidentiality), and the Director himself being bashed on that reactionary “watchdog” site for things over which he had no control (such as the HHC, implemented well before he was in office), and it’s pretty amazing that we did as well as we did.
    Take in contrast the IRS, State tax Boards and DMV. Enumerators aren’t nearly as nasty as metermaids- we came to count people, not bully them, yet we’ve had ours chased with cars and even beaten. How about a spy video of some municipal office’s operation, as well as that one from an enumerator training session?
    The point is that under ideal circumstances this would be difficult, or at least very heavy as operations go: if everyone living here could simply cooperate with simply being statistically accounted for it would be a big piece of work. But our present ideal sadly weighs personal freedom more heavily than unity of direction as a Nation; even the FBI is put on the spot for simply doing its job diligently, whereas in some of those countries we cite for census models there may not be such public participation in matters of even security.
    Census has to consider all factors of potential impact to a count, including those above as well as things like everyone’s access to internet in the first place (if we are to use the online concept so highly touted), and the quality of our own staff hired in such a rush. As a scientific, statistical entity, Census would be foolish to assume that perfection in counting such a variable as our population, multiplied by so many other variables, could be attained. We simply must endeavor to do as well as we can.

  10. JC says:

    In response to M.H. Norman. The site is up and running in that I was able to access the address. I urge you to keep trying.
    As an enumerator for the 2010 Census, I am very pleased to see a site is available for those who were not counted by questionnaire via mail or an by a personal visit from your friendly enumerator. Dr. Groves, this should be considered for the next Census. The cost savings would be tremendous. As noted on the site, every household (address) could be given a code number to enter. The information could automatically be gathered into a database. What a concept! So simple and efficient. No politics involved.
    Kudos to all enumerators who worked so hard in spite of the ‘management’. We all had a tremendous, thankless task and DID IT WELL. Give yourself a pat on the back.

  11. fl office clerk says:

    the director says “if the Census Bureau is completely transparent about its methods”, so when is that going to start?? and if they are so transparent about the methods why were Census field and office employees forbidden to talk about them? Talking about the Census was not allowed at the local level even when the information was Positive!. We had someone let go for a positive editorial in the local Sarasota paper.

  12. Nevil says:

    How do we actually know if all census has been received and account for? is there any checks in place to verify this?

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