A:  (Per Anton Treuer in Everything You Wanted to Know About Indians But Were Afraid to Ask)

(As stated above,) [sic] a few groups are well-off, many groups are improving but still disproportionately poor, and some groups have most of their citizens living in abject poverty. The advent of casino gaming has affected some Native Americans far more than others. For tribes that have a monopoly on gaming in a given region and a very small number of tribal members, casinos have provided a dramatic impact on their members’ financial status. But for most Indians who live in rural areas or come from tribes with large numbers of members, the impact has been much smaller.

Each tribe is an independent nation, with no legal obligations to other tribes. Casino profits are not shared by all tribes in America. Wealthy tribes often engage in philanthropy with less fortunate tribes, and in Wisconsin all tribes agreed to share a small percentage of revenues. But those developments have not come close to leveling the dramatic wealth disparities among tribes, even in Wisconsin.

Dr. Treuer in MinnPost series on Indian Gaming