California Gov. Jerry Brown has until the end of September to sign legislation that would require public companies based in the state to put a certain number of female directors on their boards. Before picking up the pen, he should give weight to how ineffective these quotas can be.

Such quotas have been snaking their way through Europe’s boardrooms for more than a decade. Researchers say they can help boost morale among aspiring female business leaders and potentially boost profits.

But mandates don’t effectively address two frustrating issues women face in corporate America: a stubborn pay gap and a thick glass ceiling.

For instance, in Norway—the egalitarian culture credited as the pioneer of such quotas—women CEOs are nearly nonexistent even though roughly 40% of directors are female. The Nordic nation’s pay gap is slimmer than the U.S.’s, but data from the Organization for Economic Cooperation and Development indicate Norway lags behind about 25% of the countries it tracks.

The debate over quotas is not inconsequential. California’s giant technology companies have enormous sway in our daily lives and in the stock market, but they are often criticized for being slow on advancing the careers of women and lacking foresight when it comes to how their products will affect society. Diversity in the boardroom could help Silicon Valley clean up its act.