The growth in women's participation in late working life over the past decade has been dramatic, about three-quarters higher than that of older men, and it is mostly about money, Carolyn Evans says.

''We asked a series of women in that age group why they were working and almost without exception … they had to come back to work, or they were going to retire and when they did the numbers, they didn't have enough to live on,'' said Mrs Evans, who did the research for the Australian Business Foundation.

''They had effectively arrived at a choice of living in genteel poverty for another 40 years - not starving, but no holidays, no treats and no fun. The alternative is staying at, or going back to, work in 'top-up super' mode.''

The good news from her analysis of Australian Bureau of Statistics figures and interviews was that strong jobs growth meant women in this age group could find work, but the flipside was that they had to, she said.

''You don't go back to work in those numbers for the fun of it. A lot of women in that age group pre-date important reforms,'' she said. In their early working lives, they missed out on equal pay, and in the absence of maternity leave, they had to take unpaid leave to have children.

Many full-timers were considering winding back their hours by changing jobs or opening businesses, she said.

But self-employment carries its own risks. Most female business owners are not paying themselves any superannuation, even though almost one in three say they know they should, a women's business body has found.

An online survey of almost 3000 businesswomen found only about one in five have always paid themselves contributions, while one in four do so when they can. Yolanda Vega, the chief executive of the Australian Women Chamber of Commerce and Industry, said women were setting up businesses, but their superannuation contributions were often too little or too late. Debra Jopson