Other executives frequently tell Beth Axelrod that she made “an unusual career move.” From her perspective, their reaction to her shift from consulting to human resources highlights the long road HR still must travel to become a full strategic partner with businesses. For her, though, it’s a road worth pioneering.

In an era of ever-intensifying competition for talent, companies that can appeal to and retain different kinds of workers are more likely to succeed. Understanding diversity in the workforce has been a professional interest of Axelrod’s since 1989, when she was asked, as a young McKinsey consultant, to help figure out why the firm was losing so many women and what could be done to keep them. In the late 1990s, Axelrod was a leader of McKinsey’s War for Talent project, which quantified the challenges that leading US companies faced in finding talented executives. She later moved on to executive roles at the global marketing communications group WPP and then to eBay.

In the past decade, the talent challenges facing companies around the world have only become harder to manage. Knowledge workers are ever more crucial to corporate success. In developed economies, baby boomers are beginning to retire; in developing...