Last Tuesday, Slate DoubleX founding editor Hanna Rosin and New York Times op-ed columnist Gail Collins sat down before a packed house at the New America Foundation to discuss Ms. Rosin’s long-anticipated book, The End of Men, due out September 11 from Riverhead.

As the two journalists tried to explain the persistent wage and power gap between men and women in America, their conversation returned again and again to our more progressive friends in California and Scandinavia.

Ms. Rosin asked Ms. Collins—whose feminist history America’s Women she called “her bible”—if there was an era in history when women held true political power.

“No,” Ms. Collins deadpanned, to laughter. Generally speaking, women had fared best in new societies, “where things are being started and everyone really has to chip in and work together to get stuff done.”

That might explain the better-than-average gender equality Ms. Rosin found in Silicon Valley, where she said companies have figured out the “domestic puzzle” of balancing child-rearing and work.

“They work really hard and they work really flexibly,” she said, “because the companies are fairly new and don’t have structures in place.” One female Google executive told Ms. Rosin she had gotten the company to agree to pay for her nanny and baby to accompany her on all business trips for the first two years.

But Ms. Collins was skeptical about how high Californian equality goes. Facebook’s board of directors, she said, resembles the Backstreet Boys.

Ms. Rosin said that in Norway, a law had been passed requiring major corporations to have boards that were 40% women.

“It’s always Norway,” Ms. Collins replied.

“Or Sweden,” they said, in unison.

Sweden had, in fact, been the site of another experiment of interest to Ms. Rosin, which offered financial incentives for men to take paternity leave. Women stayed home during the child’s first year or so of life, and then men took over for the toddling years, congregating in big indoor playgrounds and generally behaving like the mommy mobs of Prospect Park.

“You expect the guys would be talking about football,” Ms. Rosin said, “but they’re like, ‘What kind of stroller you got?’”

But back to Norway.

One year after the board of directors law was enacted, it turned out that companies with gender-equal boards were—gasp—less profitable than the male-dominated ones. They had been less reactive in the face of the recession, reducing salaries and hours across the board instead of laying off trained workers.

“Not the Bain Capital way of doing it,” said Ms. Collins, a noted Mitt Romney-watcher.

It remains to be seen whether the female-led companies will do better in the long run.

One audience member wondered if there was any hard data on “Swedenification” of gender roles. Were their children, the boys and the girls, doing better? Did it make anybody happier?

“I always get the impression Swedes are very unhappy,” Ms. Collins said. “It’s a very cold country.”

“There are saunas,” the audience member pointed out.

But according to Ms. Rosin, one nice thing about “The End of Men” is that men—well, Swedish ones, anyway—are learning that there are worse things than having to be the woman in the relationship.

“They forced it on them and now they’re into it,” she said. “It turns out to be not so bad.”