A number of academics have pointed out that the ethnicity classification employed in the census and other official statistics in the UK since 1991 involve conflation between the concepts of ethnicity and
race. Aspinall notes that sustained academic attention has been focused on "how the censuses measure ethnicity, especially the use of dimensions that many claim have little to do with ethnicity, such as skin colour, race, and nationality". The year 2001 was the first census which asked about mixed ethnic identity. In that census, 677,177 classified themselves as of mixed ethnicity, making up 1.2 percent of the country's population. The 2011 Census gave the figure as 2.2% for England and Wales.
Office for National Statistics estimates suggest that 956,700 mixed-ethnicity people were resident in England (as opposed to the whole of the country) as of mid-2009, compared to 654,000 at mid-2001. As of May 2011, this figure surpassed 1 million. It was estimated in 2007 that, by 2020, 1.24 million people in the UK would be of mixed race. Research conducted by the
BBC, however, suggests that the mixed race population could be up to twice the official estimate, up to 2 million. According to
The Economist in October 2020, the 2011 census figure "is probably an undercount, since not all children of mixed marriages will have ticked one of the mixed categories, and the number is likely to have grown since the census". 3.5 percent of all births in England and Wales in 2005 were mixed-ethnicity babies, with 0.9 percent being 'Mixed White and Black Caribbean', 0.5 percent '
Mixed White and Black African', 0.8 percent 'Mixed White and Asian', and 1.3 percent any other mixed background. ==Population==