Ancedotes are personal stories, like "oh, my dad was down at the post office the other day, and he saw..."

This is not a personal story, not an anecdote. I'm reporting on a study that looked at incarceration rates for drug use vs the drug use itself.

Why is that important? Because the study itself is solid, and it shows that there is some sort of bias between police/policing and african-american communities.

Sure, maybe that bias doesn't show up in other areas like firearm-related crimes. Or: maybe it does, and we haven't yet figured out how. Or, maybe it plays an indirect role, further eroding the relationship between the AA communities and the police, gradually building up a mutual dynamic that subjects black people to an unhealthy chronic level of stress and despair and harassment while also "justifying" the prejudicial activities of the cops.

There are whole books written about this. But at a minimum, I can't imagine just brushing over a 4x higher arrest rate for the same level of crime. That's pretty damn big.

You're literally just describing a chicken-and-egg problem. Curious what your brain thinks is the reason African-American communities are policed more intensely. Surely every police organization in the United States is just racist.