The U.S. Census Bureau released research from its 2010 Census Race and Hispanic Origin Alternative Questionnaire Experiment, which provides a comparison of different census questionnaire design strategies for collecting census data on race and Hispanic origin.
The Bureau is recommending that Hispanics now be treated as a distinct group and therefore drop the ethnicity question all together. This would mean Hispanics would just be asked about race: black, white or Hispanic. The recommendation is made so as to better count the different demographics in the U.S.
The study tested several versions of an experimental combined question on race and Hispanic origin. The current classification treats race and Hispanic origin as two separate and distinct concepts.
The results showed that a higher number of individuals were more likely to respond to a combined race and Hispanic origin question than to separate questions.
Since the percent of the population who identified as Hispanic was not significantly different across questionnaires, this indicates the Census says that the total proportion of Hispanics was not reduced in a combined question approach, hence the recommendation.