Subject: Re: Berkshire Safe Withdrawl Rate
The best example is the one in Berkshire's chairman's letter where he discusses how, despite having given away 5% of his [then current] number of shares each year for many years, the market value of his shareholding had gone up, not down. He doesn't do an inflation adjustment in that example, but the numbers weren't even close, so it didn't matter.

I've written a bunch of things on that general subject.

One of my favourite approaches is to smooth the real book value per share (I've advocated a 16-quarter WMA), and based your liquidation amount on how much that smoothed value has risen since your last withdrawal. This in effect keeps the real (smoothed) value of your portfolio constant in real terms, so it lasts forever. I also put in a tweak so that there is a floor on any rolling year's withdrawals, 4% of the original real portfolio value, just so you don't have dry spells.

The nice thing about this is that it adapts, gently, to any change in the rate of change of Berkshire's growth in value per share. If Berkshire stops growing quickly the withdrawals shrink commensurably, the portfolio doesn't go broke. At least so long as trend real value rises 4%/year, which isn't much of a hurdle rate.

This is particularly appropriate as I think it would be quite nice to live forever. With good health of course, nobody wants to be Tithonus.

Jim