It's not the same thing at all. If you pay 20% in taxes, and we're considering $1,000 of earnings, then I'm talking about paying $200 to charity instead of paying $200 in taxes.

You're talking about paying the full $1,000 to charity to avoid $200 in taxes. Totally different thing, and vastly more expensive.

Plus, his taxes are all in one year. To spend that kind of money effectively on charity would take many, many years, so it's still not a viable alternative.

You could donate it to a charity, but they wouldnt have to spend it. This is what gates and soros do. Its basically a charity that funds other charities as they see fit.

A charitable trust with pretax dollars would be an even better idea however.