Annuities provide security against living too long

Harold Evensky, a certified financial planner (CFP) who is considered the father of the financial planning industry, used to oppose the use of immediate annuities. But he has changed his mind and now recommends immediate annuities. Evensky considers the immediate annuity "a powerful vehicle that’s virtually the only strategy to ensure maintaining one’s standard of living in retirement." He says: My change of thinking came with the advent of lower cost annuities from firms like Vanguard, TIAA-CREF and others. They’re offering immediate annuities — also known as payout annuities, income annuities, longevity annuities and longevity insurance" as "the only way that investors can manage their mortality risk — living longer — and maintain the income they need for the rest of their lives."
http://www.thinkadvisor.com/2015/03/24/evensky-in-reversal-sees-annuities-as-vital-for-re