Just a few related notes ...

Buffet has pledged to give away 99% of his wealth:

http://www.reuters.com/article/idUSN0224010620100702

http://givingpledge.org/

I've read that a number of Presidents have proposed one form or another of a guaranteed minimum income. This includes both Nixon and Carter.

And quoting from Wikipedia,

"American revolutionary Thomas Paine advocated a basic income guarantee to all US citizens as compensation for "loss of his or her natural inheritance, by the introduction of the system of landed property" (Agrarian Justice, 1795)."