A new study of census data finds 10 million Americans answered questions about their racial identity differently in 2010 than they had a decade earlier.
University of Minnesota sociologist Carolyn Liebler, who co-authored the study, tells Pew Research Center that Americans of every race and ethnic group changed their responses, but Hispanics were most likely to answer differently.
People of mixed race, American Indians, and Pacific Islanders were also among those most likely to change their answers, Pew says.
Why did people change their race from one census to the next? Researchers say there's no easy answer but offered a few possibilities.
Liebler tells Pew that some of those who changed categories were children in 2000. She theorizes that a parent may have filled out the form that year and the respondent identified with a different race or ethnic group when compiling their own form ten years later.
Others think the most likely explanation for the change is that respondents are confused by the Census Bureau's questions, which ask separately about race and ethnicity.
Former Census Director Kenneth Prewitt wrote an op-ed piece in the New York Times last year calling for an overhaul of the census' questions about race. He called the designation of Hispanic as an ethnicity "particularly tortured."
But some Latino civil rights groups and a number of scholars are not comfortable with making Hispanic a racial category instead of an ethnic one, noting it would do away with check-off boxes for national origin such as Mexican, Cuban, or Puerto Rican.
The director of the National Institute for Latino Policy told Voxxi last year “There is no unanimity on what any of this stuff means.”
Pew Research Center reported in March that the Census Bureau is considering changes to its questions on race, particularly since more than 6 percent of 2010 respondents listed themselves only as "some other race."