OPINION: PEOPLE travel from all over the world to attend the annual shareholder meetings of the legendary billionaire investor Warren Buffet.

Last weekend, more than 35,000 turned up to a stadium in the midwest city of Omaha, Nebraska, to hear his investment wisdom.

And Buffett's latest stock tip is a doozy: women.

In an article penned for US magazine Fortune, Mr Buffett has identified women as society's greatest untapped resource.

No CEO, he writes, wants to operate their factory below capacity. But this is just what society does by limiting the work ambitions and dreams of half its population.

Unleashing the hidden talents of women offers the best hope for a new wave of productivity in America: "We've seen what can be accomplished when we use 50 per cent of our human capacity. If you visualise what 100 per cent can do, you'll join me as an unbridled optimist about America's future."

Back at home in Australia, progress has been made to advance women into the workforce.

Three decades ago, just one in three Australian workers were female. Today, women make up almost half - 45 per cent - of the workforce.

But progress has stalled.

The workforce participation rate among men remains stubbornly higher than women, at 72 per cent compared to women's 59 per cent.

Imagine if we harnessed the full capabilities of the other half of our population?

It's time we stopped viewing women's rights as purely a social issue, but also an economic issue.

According to the chief economist at Goldman Sachs, Tim Toohey, closing the gap between male and female participation rates would increase economic activity by $180 billion.

Toohey's groundbreaking 2009 report, Australia's Hidden Resource: The Economic Case for Increasing Female Participation, found Australia is only two thirds of the way towards unlocking the hidden value of the female labour pool.

So what is stopping us?

A bit of blame-the-victim is par for the course when it comes to discussing equality for women in the workforce. Women, we are told, are inherently less ambitious and less competitive than men.

Poppycock.

It is true studies have found women are less likely to ask for pay rises than men and less likely to put themselves forward for jobs they do not feel qualified for.

But according to psychologist and the author of Delusions of Gender, Cordelia Fine, women's reluctance to put themselves forward is due less to nature than to nurture. It's the subtle social messages we send our girls every time we praise their beauty, not their brains.

A future female CEO dies every time a young girl sees Disney on Ice's Princesses and Heroes, (because as everyone knows, you can't be both a hero and a princess).

Women, says Buffett, must learn to play the game and have more confidence in their own abilities: "Women should never forget that it is common for powerful and seemingly self-assured males to have more than a bit of the Wizard of Oz in them. Pull the curtain aside, and you'll often discover they are not supermen after all. (Just ask their wives!)"

Women, Buffett adds, will invariably encounter blatant discrimination as they make their way up the greasy pole.

"Resistance among the powerful is natural when change clashes with their self-interest. Business, politics, and, yes, religions provide many examples of such defensive behavior. After all, who wants to double the number of competitors for top positions?"

Buffett urges his fellow males to to get on board the equality train because it will boost the economy as a whole.

But women need actions more than words from our menfolk.

Despite decades of exhortations to get men to shoulder more of the responsibility for child rearing, domestic duties remain, for the large part, the domain of women.

We've doubled up the load on women, sending them to work while failing to lighten their load of domestic duties at home. No wonder more women feel like they can't "have it all". More than 70 per cent of working mothers say they feel stressed some or all of the time.

This strain of balancing work and family is the main reason for the gender pay gap, according to a study of 2000 graduates from the MBA program at the University of Chicago. Study authors and economists Marianne Bertrand, Claudia Goldin and Lawrence Katz found only a small gap between female and male graduate earnings at the start of their careers - although the gap still favoured men.

But the real differences emerged later in life, when women took time out to have children. Ten to 15 years into their careers, the earnings gap between female and male graduates had widened to 40 per cent.

"Almost all of that huge difference can be fully explained by the greater number of career interruptions and lower weekly hours experienced by the women," the economists found.

Interestingly, the women were found to return to work soon after their first birth. But after a year or so, they average MBA mum began to shorten her hours in paid work. Those with high income husbands were the most likely to leave the workforce altogether, eroding their own earning potential permanently.

Reforms such as Labor's paid parental leave scheme, paid at the minimum wage, and Abbott's more generous scheme to pay mothers their own salary for six months offer vital support for women in a stressful phase in their life. It is social recompense for the private investments women make to give life to the future workforce.

But Abbott should join Warren Buffett in encouraging fathers to take up his parental scheme too.

Because if women are to truly "lean in" in the workforce, men must learn to "lean in" at home too.