A letter from a listener prompted Mary to ponder the differences between women and men and they way they handle their finances.
The listener, a single woman, ponders why the elderly and single women are more likely than others to spend too little.
And she tells a story of how she's financially outdone a man she dated.
“It occurred to me that both elderly people and single women are devalued and marginalised in many societies, and may therefore feel, consciously or unconsciously, that they are on their own if they run into domestic or financial problems. That could be why they become fixated on saving money.
Another reason why women could be afraid to spend, perhaps, is that there is still a perception, left over from our patriarchal past, that women can't really manage their own household and finances - that these things should really be in male hands.
I'm a single woman in my late forties. I don't see being single as a problem, but many people seem to think it is. I'm advised that I'm too fussy, too opinionated, that I talk too much.
The last guy I dated turned out to have no money, and told me I could support him financially until he turned 65, at which point his retirement investment, something to do with pine trees and the Kyoto Protocol, would mature, giving him more money than he could ever spend.
That was before the global financial crisis of 2008. In 2008, the value of my managed fund lost 25 percent of its value overnight, while his "investment" shrank to nothing.
Mine eventually climbed back to something near its original value, before I cashed it in and bought my flat, where I now live in blissful spinsterhood."
Mary Holm says men do tend to trade more often and to take more risk - for good and bad - but “there are heaps of exceptions”.
“There’s some stark differences between the way men and women invest. Women tend to be more conservative and take less risk than men and there’s lots of research to suggest that and also women are more likely to get into investments and stay in them.
“Men can take on too much risk at times - they can get over-confident, some of them, and think that they know which shares are best and so on.
“That kind of behaviour, trying to time markets, you nearly always end up with less than if you just get in there buy some good investments and just stick with them.”
The other side of the coin is too much conservatism can cost in the long run, she says.
“Women are quite often stuck in low risk KiwiSaver funds or bank term deposits and could take more risk and end up with more savings at the other end.”
Research also shows, she says, women are more likely seek financial advice than men, are more patient with their money and more likely to set goals.
“Women are more likely to succeed with their goals if they tell friends and family about their goals and also if they get some encouragement.
Men are more likely to succeed if they have a very specific goal and if they focus on the rewards for achieving that goal.”
And women are also less likely to feel confident about their retirement savings than men, she says.
“ANZ did a survey in which to the question “are you confident of your retirement savings goal?” 55 percent of men said yes compared with 41 of women.”
You can listen to more of Mary's podcasts here.