"A global effort to bolster the number of women on corporate boards is taking longer than it should," Bloomberg Gadfly columnist Gillian Tan writes. "But the recent performance of companies that lead their peers on this measure may accelerate change." An MSCI study shows just seven companies in its key global index—comprised of more than 2,500 members—have boards that are dominated by women. But of these seven, more than half have outperformed their industry peers. Although it's a small sample, the outperformance of this group is a supportive data point for heavyweight investors BlackRock, Vanguard Group, and State Street, which are increasingly committed to backing more diversity on boards. Read the original column from Bloomberg.