On this International Women’s Day in 2023, the “glass ceiling” is alive and well, blocking women from advancement across the corporate world. This is true at Fortune 500 companies, where they experience slower career climbs than their male peers, among executives in general—where more are excluded from informal networks and mentors—and among MBA graduates’ careers, where women end up paid less. That’s all despite having similar qualifications, skills and experience.

Smart, savvy businesses should hire more women for those top jobs, for reasons that go beyond even fairness. That’s because a wealth of research suggests that hiring women for the top perch pays off—a hidden, discriminated-against, key to success in the business world.

One Harvard Business Review study, for example, reported that companies with a higher proportion of women in principal leadership positions “are more profitable, more socially responsible, and provide safer, higher-quality customer experiences.” Focused on innovation, the study researchers looked at 163 multinational companies over 13 years to determine how these firms’ long-term strategies shifted after women joined their top management. They discovered the firms became more open to change and less vulnerable to risk, shifting their focus from the financial engineering of mergers and acquisitions to the real engineering of research and development.