It was a bit surprising for me to find out that, when it comes to ethnic and cultural diversity, America is actually less diverse than Mexico or Canada (driven largely by massive immigrant populations in Vancouver and Toronto).
https://en.wikipedia.org/wiki/List_of_c ... sity_level
Or if you prefer a map...
https://www.washingtonpost.com/news/wor ... countries/

In terms of economic and social outcomes, what role do you think ethnic and cultural diversity plays? Is homogeneity only important during the formative years of a nation, or does it maintain it's importance into the present day?