During their working years, women tend to earn less than men, and when they retire, they're more likely to live in poverty.

These are women who raised children and cared for sick and elderly family members. They often take what savings and income they do have and spend it on things besides their own retirement security.

The National Institute on Retirement Security — a nonprofit research center — reports that women are 80 percent more likely than men to be impoverished at age 65 and older. Women age 75 to 79 are three times more likely.

Experts cite a pay gap as a major cause for retirement insecurity. But other factors play a role, from single parenthood and divorce to the fact that women typically live longer than men.