Nobody knows how long they’ll live, which makes bonds a more risky prospect for retirees’ long term planning. Benjamin Harris cites work by Vanya Horneff, Raimond Maurer and Wharton’s Olivia S. Mitchell (view study) showing the advantage of putting 10% of 401(k) wealth into deferred annuities instead. Click here to read the Wall Street Journal’s Wealth Management blog, Wealth Management