Women Get Corporate Board Seats Mostly When It’s Required by Law

Diversity advocates have been trying for two decades to sell the corporate world on gender balance in the boardroom. Maybe they should be lobbying lawmakers instead.

A new study by Egon Zehnder points out that among countries that average three or more women on large company boards -- thought to be the threshold at which diversity starts to yield higher returns -- all but one operate under government-mandated quota systems.

“When we look at the board seats that have turned over, only about a quarter of them are filled by women,” said Cynthia Soledad, a co-leader of the Egon ...