It pays to hire women in countries that won't

Even after accounting for unrelated variables, the researchers found that a 10 percent nominal increase in the percentage of female managers (at the level of the then-prevailing glass ceiling) was associated with a 1 percent nominal increase in ROA.

"The results are pretty strong that even when you control for anything that's fixed about a company, it appears that increasing your female managers leads to higher profitability over time," says Siegel.

Netflix lets its staff take as much holiday as they want, whenever they want—and it works

Ever more companies are realising that autonomy isn't the opposite of accountability – it's the pathway to it. "Rules and policies and regulations and stipulations are innovation killers. People do their best work when they're unencumbered," says Steve Swasey, Netflix's vice-president for corporate communication. "If you're spending a lot of time accounting for the time you're spending, that's time you're not innovating."

The same goes for expenses. Employees typically don't need to get approval to spend money on entertainment, travel, or gifts. Instead, the guidance is simpler: act in Netflix's best interest. It sounds delightfully adult. And it is - in every regard. People who don't produce are shown the door. "Adequate performance," the company says, "gets a generous severance package."

The idea is that freedom and responsibility, long considered fundamentally incompatible, actually go together quite well.