This seems to be the largest potential issue then with my understanding of requiring research a-priori to match an assumed outcome or ideal. I wonder if an academic wanted to rigorously attempt to isolate between these, would they be allowed to publish the results were found that systemic issues were not significant. It seems potentially dangerous if we stifle publications of studies that find minimal impact of racism because it could have the impact of only highlighting the cases of racism, but not the net impact.
The assumption alone is wrong yet any other assumption inevitably leads to stigmatisation and segregation.
Whatever study anyone comes up with it will inevitably turn into a discussion if either racism or discrimination.