Earlier quoted context omitted.
Donating $5.7B to save an absolute max (37% tax bracket; he's probably much lower with most income via capital gains) of about $2.1B in taxes doesn't make financial sense, unless you've got a plan to siphon off at least $3.6B tax-free out of the charity. Why do people think a $1B donation saves $1B in tax?
He doesn’t need to shiphon anything. All the “donated” money is still in his control. In order to be effective at tax deference you need to separate the concept of who ownes the money and who controls it. As long as you still control it, it doesn’t matter who ownes it. That’s why a donner advised funds and similar concepts are used to reduce taxes or defer them. In addition it’s also great for asset protection. For e…
Another thing people are missing is that it's not an income tax dodge, but rather an estate tax dodge. The money will remain in control of his heirs, assuring they'll never go hungry or want for a place in the world.
It also creates more opportunities to play with asset valuations to evade taxes (eg separate the financial and voting interest of some stock in a closely held company, then claim the financial interest is worth very little without the control interest). But it's impossible to know if this is actually being done without seeing tax filings, including his (eventual) estate tax filing.