Variable annuities are a form of life insurance that includes a lump-sum death benefit and tax-deferred investments, often mutual funds, which are supposed to provide income during a client's lifetime.
In earlier research, Mr. Mahaney highlighted another benefit to deferring benefits until later: If you expect much of your retirement income to come from tax-deferred savings, you might be better off using those assets first and delaying all, or a large chunk, of your Social Security.