Gender issues took center stage Friday at the World Economic Forum in Davos, Switzerland, as a panel of all-star voices on the topic chatted about the benefits of gender diversity in the workplace, how to get more women into leadership roles and the systematic biases that women face.

Facebook chief operating officer and Lean In author Sheryl Sandberg spoke with Gates Foundation co-chair Melinda Gates, Canadian Prime Minister Justin Trudeau — who recently drew attention for appointing a cabinet that showed true gender parity — as well as others about why we're still dealing with this issue in 2016.

One of Sandberg's big arguments: Gender diversity is not just a good thing to do, or the of-the-moment thing to do. It's also a smart thing to do that will help your company, your marriage and your children. "Do it because it's going to help you," she said.

Research shows that couples with more equal relationships have stronger marriages, Sandberg said, and that children, particularly daughters, benefit when fathers take a more active role at home. "They do better emotionally, they have stronger relationships with their parents, they do better in school, and they do better professionally," she told the audience. "So the reason to work towards equality — if you're a woman or a man — is because it's going to help you."

Meanwhile, Sandberg addressed the ongoing debate over whether it's effective to implement requirements for having a certain number of women on corporate boards or in houses of government. She is not an advocate.

In Norway, for instance, company boards and the Norwegian legislature have had quotas for the past decade that they need to comprise at least 40 percent women. "Do you know how many women run their top companies?" Sandberg asked. "Three-point-four percent. [It] has not moved the numbers. Has not moved the numbers anywhere else in the corporation."

While they work in some cases, Sandberg added, "we can’t rely on quotas because they’re not moving the things which they're not applied to." 

Finally, she addressed how early and pervasive the biases are against women. "Starting with babies crawling. Mothers will systematically overestimate their son's crawling and underestimate their daughter's," she said. And then later in life, men tend to overestimate their GPAs and sales quotas whereas women tend to underestimate them.

"When men succeed, we—meaning the person and other people—attribute that success to the man's core skills," she said. "He succeeded because he was great. He has skills. With women, we attribute that success—both themselves and others—to working hard, help from others and getting lucky. That's a really big difference." 

Trudeau held court on the issue, too, speaking among other things about a campaign he oversaw called "Ask Her to Run," which aimed to encourage more women to run for office in Canada. "Study after study has shown that if you ask a man if he wants to run for office, his first question is likely to be: Well, do I have to wear a tie every day?' " Trudeau said.

"If you ask a woman if she wants to run for office, her first question is usually, 'Really, why me?' So, Trudeau concluded, "We said: Okay, if we know you have to ask more often, let's ask more often."

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