Fig. 4.

Hierarchical clustering on the matrix $M^{TP}$, defined in Section 3, for all $N=114$ states in our collection. The majority cluster contains two subclusters A1 and A2, broadly consisting of US states and Indian states, respectively. Brazilian states, labelled with two letters for visibility, are interleaved among A1 and A2 and also the two outlier clusters B and C.