I am running a regression where I am trying to identify the influence of the proximity to Tuskegee, Macon County and the percentage of African American population on the Covid-19 vaccination rate on county level.

reg vaccination_perc_points c.dist_Tuskegee##c.perc_points_afri_am i.urban_rual i.education_low_high median_income perc_points_male social_capital_index perc_points_am_indian_alaka_native perc_points_asian, robust

Now I would like to apply state effects. I am wondering whether I should apply random or fixed effects. I control for all possible realizations of states which would indicate fixed effects. But I am only interested in a fraction of my population (African American) which favors, as far as I unterstood, random effects.

I would very much appreciate your advice regarding fixed or random effects.