&gt; How else are you going to know if there are disparities between racial groups if you don't measure it?


Because the simple idea of differentiating people based on their "race" is plain stupid. We don't observe disparities in racial groups, we observe the disparities among different social environment of people instead. The skin color of a person is a useless metric.

Where you're born, where you grew up, where you went to school,  where you currently live, what your parents did as a job, their level of education etc.. will tell you a million time more about a person, than his skin color..

A black person that grew up in a nice suburb of Paris like Versaille or Neuilly, will have a lot more in common with other people living there even if they are for the huige majority white, than with another black person that grew up in a poor area.

If black people in France mostly live in the poorer area of the country, it's not because they are black, that's because they are immigrants. So instead of putting all black people into the same category which doesn't make sense, the category we will observe is the immigrants : In that group you will have arabs, and black and yet it will be a much more homogeneous group that your so called "racial groups". And you will be able to make much more meaningful analysis from it.