"Some [Census Bureau] experts say officials are right to go back to the drawing table. 'Whenever you have people who can't find themselves in the question, it's a bad question,' said Mary C. Waters, a sociology professor at Harvard who specializes in the challenges of measuring race and ethnicity.
The problem is more than academic - the census data on race serves many purposes, including determining the makeup of voting districts, and monitoring discriminatory practices in hiring and racial disparities in education and health. When respondents do not choose a race, the Census Bureau assigns them one, based on factors like the racial makeup of their neighborhood, inevitably leading to a less accurate count."