The subject caused me to go back and re-read the 2006 annual report, in which the donation plan was discussed.

The thing most people overlook is Buffett saying a 5% "Berkshire share" withdrawal rate will last a very, very long time.

"The value of Berkshire shares will, of course, vary from year to year. And, as noted, the number of shares distributed will diminish by 5% per year. Nevertheless, I believe that you can reasonably expect the value of Berkshire shares to increase, in an irregular manner, by an amount that more than compensates for the decline in the number of shares that will be distributed."

In other words, you will always have less shares, but those shares are worth much more.

There's been so much ink spilled over the 4% SWR and asset allocations and all that stuff. A very simple retirement plan is 100% Berkshire and 5% withdrawal.