Retirement plan portfolios that include income annuities tend to produce better results than portfolios filled only with stocks and bonds.

Researchers at Massachusetts Mutual Life Insurance Company, Springfield, Mass., have reported that finding in an analysis of the performance of a hypothetical $100,000 retirement account over 181 time periods between 1965 and 2006.

About 25% of the portfolios holding just stocks and bonds ran out of money, but all of the portfolios that used the strategy of “laddering” into annuities met the hypothetical savers’ income goals, MassMutual researchers report.

The analysis did not incorporate the possibility of annuity issuer default, but, under the conditions studied, an annuity strategy produced 5 times more income than the strategy of living off of interest on a deposit generated, the researchers report.