American corporations can claim progress with the addition of more women to their boardrooms, but at less than 20%, the rate of female membership pales in comparison to some European counterparts.

Women constitute an average of 19.2% of board positions on U.S. companies in the S&P 500, according to the research group Catalyst. More than 25% of the S&P 500 average 26% female membership. Only 18 companies still have all-male boards.

The percentage of women on S&P 500 boards is considerably smaller than boardrooms in Norway, which averages 35%, or Finland and France (just under 30%) or Sweden (28.8%). The United Kingdom (22.8%) and Canada (20.8%) also have more women on corporate boards than the U.S.

 “The critical question is how we get past 19 percent for the S&P 500…to something more approaching critical mass,” Brande Stellings, vice president of Catalyst Corporate Board Services, told ThinkProgress. “The thing we have to next pay attention to is to make sure companies don’t stop at one and see having one on their board as a safe harbor.”

One thing the U.S. could do is mandate a higher rate for American corporations, which Norway did when it imposed the world’s first gender quota seven years ago. Businesses there must meet a 40% standard. Some other European countries have adopted their own floor for female representation in boardrooms.

U.S. companies might even find it to their advantage to have more women on their boards. Studies have shown that companies with more women on their boards do better than those governed by the Old Boys’ Club.

-Noel Brinkerhoff

To Learn More:

What’s Behind The Gender Inequality In American Boardrooms? (by Bryce Covert, ThinkProgress)

2014 Catalyst Census: Women Board Directors (Catalyst)

Women’s Place Is Still Not in California Corporate Leadership (by Ken Broder, AllGov California)

Companies with Women CEOs Outperform those Led by Men (by Noel Brinkerhoff, AllGov)