And here are our final results for this new Spatial Clustering Index.

In brown are the districts where 100% of its the census tracts have income below the global mean and are surrounded by other low income census tracts.

In light yellow are the districts where none of its census tracts were low income tracts surrounded by other low income tracts.

We think that for the purpose of this study, this new index may be a reasonably  good spatial measure in the evenness/clustering dimension.