Call it a stealth development in U.S. corporate governance. Media, investors, and boards have been scrambling to handle—or head off—annual meeting uprisings over executive pay. But beyond the headlines, a revolutionary structural change is quietly sweeping through boardrooms. The shift can be summarized in one concise truth: that the overwhelming U.S. practice is no longer to combine the chair and CEO jobs in one person.
Today, 40 percent of S&P 500 companies split the roles between two individuals. Seven years ago the comparable figure was just 27 percent. True, in 2010 only about half of the separate chairs—19 percent of ...