The 2010 census failed to count over 1.5 million minorities, as the Census Bureau struggled to count black Americans, Hispanics, renters and young men.
The Census Bureau on Tuesday released an extensive assessment of its high-stakes, once-a-decade headcount of the U.S. population. Based on a sample survey, the government analysis has been a source of political controversy in the past over whether to "statistically adjust" census results to correct for undercounts, which usually involve minorities who tend to vote Democratic.
The findings show the 2010 census over-counted the total U.S. population by 36,000 people, or 0.01 percent, due mostly to duplicate counts of affluent whites owning multiple homes. That is an improvement from a census over-count of 0.5 percent in 2000.
However, the census missed about 2.1 percent of black Americans and 1.5 percent of Hispanics, together accounting for some 1.5 million people. The percentages are statistically comparable to 2000, despite an aggressive advertising and minority outreach effort in 2010 that pushed total census costs to an unprecedented $15 billion.
Also under-counted were about 5 percent of American Indians living on reservations and nearly 2 percent of minorities who marked themselves as "some other race."
"While the overall coverage of the census was exemplary, the traditional hard-to-count groups, like renters were counted less well," said Census Bureau director Robert Groves. "Because ethnic and racial minorities disproportionately live in hard-to-count circumstances, they too were undercounted relative to the majority population."
"Our belief is that without our outreach, our numbers would have been much, much worse," he added.
The South, led by the District of Columbia, Texas, Georgia, Virginia, North Carolina and Florida, was more likely to have people who were missed. The Midwest and Northeast as a whole posted small over-counts.
The findings come after more than 100 cities including New York challenged the official 2010 results as too low.
The Census Bureau, which recently rejected New York's request to revise the city's count, says the latest analysis will not affect the government's official U.S. population tally of 308.7 million.
Nor will the analysis affect how the federal government distributes more than $400 billion to states for roads, schools and social programs.
The Supreme Court ruled in 1999 that federal law barred the use of sample surveys to adjust census results for purposes of allocating House seats; it left the door open to adjustments for other uses such as congressional redistricting or distribution of federal funds. Shortly after taking office in mid-2009, Groves ruled out statistical adjustments in 2010 for redistricting, citing a lack of preparation time.
On Tuesday, the Census Bureau noted how its efforts to count U.S. residents have improved over time. An undercount of the total U.S. population reached as high as 5.4 percent in 1940, the first time the accuracy of a census was formally measured, and then gradually decreased before an over-count was posted in 2000. American blacks are still the most likely to be missed; their undercounts have improved from a high of 8.4 percent in 1940 but at a slower pace than that of whites.
The government takes a census survey every 10 years. The bureau sends census takers and questionnaires to every U.S. household, though not everyone responds. In 2010, the government faced special challenges of counting transient families displaced by widespread mortgage foreclosures, non-English speaking immigrants fearful of enforcement raids and distrustful Americans opposed to government surveys.
Typically, census-takers following up with people who did not mail back a form encounter more difficulty getting into locked city apartment buildings, where more minorities tend to live. People who live in apartments tend also to be younger, have young children and move more often.
People who are counted twice typically include college students and people with two homes.
Based on reporting by the Associated Press.