Why is Hispanic or Asian 4th generation is diverse when Middle Eastern, Eastern European first gen is considered not because they are for now white. Also within states you have places like Detroit that are majority African American but less diverse than Houston or LA for instance. And to use an "inequality" rating sounds to me a loaded, left-leaning term.
That's a very good point. I think they should have coupled these results with the levels of integration/segregation in each state to get a clearer picture of a state's diversity.
