Newswise — A group of two dozen corporate leaders, including Warren Buffett, is trying to influence American companies to increase the number of women in positions of senior leadership.

The effort, called the 30% Club, is an expansion of an effort in Great Britain to increase female corporate board representation there to 30 percent by the end of 2015.

But can it work in the United States? Maybe, with more defined objectives, says an expert on women in the workplace at Washington University in St. Louis.

“I think this is a good start,” said Michelle Duguid, PhD, assistant professor of organizational behavior at Olin Business School and author of the paper “Female Tokens in High-Prestige Work Groups: Catalysts or Inhibitors of Group Diversification?”

“In order to increase representation of women at the highest levels of organizations,” she said, “it is very important for business leaders at the level of chief executive and chairman to show their commitment to the outcome.”

By making this public commitment, business leaders themselves will put more effort into reaching this goal, Duguid said.

“However, unlike the club launched in Britain — which has the specific objective of getting 30 percent female representation on the boards of FTSE-100 companies by the end of 2015 — the U.S. group does not seem to have very definite goals,” Duguid said.

According to the British club, there are now 92 members of the 30% Club in the U.K. The FTSE-100, a stock index in London, has moved to 20.8 percent women directors as of March 2014 from 12.5 percent in 2010, with the 30% Club seen as a driving force behind the change.

“Specifically, the United States group does not have a percentage goal for women in leadership positions, and they have not specified the types of leadership positions they intend to focus on,” Duguid said. “For example, does female senior leadership mean representation in the corporate suite and boardroom?

“Individuals tend to work harder to meet clear and concrete goals vs. ambiguous goals,” she said. “Therefore, I am not sure we will see the dramatic increases that we are noticing in the U.K.”

“We should also keep in mind,” Duguid said, “that as women move into the higher levels of organizations they should receive comparable compensation to their male counterparts.”