Glenn Ruffenach wrote an article for the new issue of SmartMoney Magazine called, "Is the 4 Percent Rule Viable?"
I think the answer is that it depends on your perspective. And I do think the article provides some pretty sensible advice. It didn't get too much into the nitty gritty of why my 1.8% number is not really incompatible with the Williams and Finke 7% number. For more details on that, it is basically what I was talking about here on Monday, and Doug Nordman also has a great explanation, "Is the 4% Withdrawal Rate Really Safe?"
One other brief matter. Perhaps taking inspiration from Carl Richards' The Behavior Gap (though he is much better at it), on the train ride to work today, I drew this:
It seems like retirement income strategies boil down to where you want to fall on the spectrum between having control of your assets and have guaranteed (inflation-adjusted) protections for life. More research should focus on the potential spending power and the cost-effectiveness of the different strategies on the frontier for these competing tradeoffs.