Q. Wealth: statistics and info

Use Statista.
Search for wealth.

Use Passport.
Search for wealth.

See the World Wealth Report by Capgemini. (free registration required)

Go to Legatum Prosperity Index from Prosperity Institute.

Wealth and Asset Ownership data from the U.S. Census Bureau.

Global Wealth Report from UBS.

Statistics of Income (SOI) Personal Wealth Statistics by IRS (U.S.) - includes data tables and papers on personal wealth trends.

While we do not have access to certain surveys of the affluent, as published by the Luxury Institute or Ipsos Affluent Survey, you may be able to find some data from these surveys cited in articles within the Business Source Ultimate
Search for luxury institute or mendelsohn affluent survey