Thirty law firms are piloting a new rule requiring 30% of leadership candidates consist of minorities and women. The Mansfield rule, named after the first female lawyer, applies to both leadership roles and promotions to equity partner.
Heather Haveman, associate professor of organizational behavior at Cornell's Johnson School, and her colleagues found "that a 33 percent increase in the proportion of women at the level of the job being filled, for example, led to a 77 percent increase in the probability of a woman being promoted to that job. This was true regardless of whether a firm had many or only a few female employees at those management levels. 'Clearly, the presence of women at a particular level in management ranks generates more women at that level,' Haveman said. The study also found that, contrary to common wisdom, neither the number of women at levels above the position being filled (who have been seen as mentors, advocates or role models) nor the number of women below the position being filled (who constitute the promotion pool) had strong effects on the chances of a woman being hired or promoted to that position."