The CEO is Only One Person

Management is important, which is why Warren Buffett puts such stock in the character of the people who run the companies he invests in. But management isn’t nearly as important as many investors think, which is why Benjamin Graham, Mr. Buffett’s mentor, paid so little attention to it. In fact, Mr. Graham seldom bothered to meet the managers of the companies he invested in, partly because he felt they would tell him only what they wished him to hear and partly because he didn’t want his judgments of business value to be influenced by impressions of personal character.

If you took the CEOs with the best track records and brought them in to run the businesses with the worst performance, how often would those companies become more profitable? According to economist Antoinette Schoar of Massachusetts Institute of Technology’s Sloan School of Management, who has studied the effects of hundreds of management changes, the answer is roughly 60%. That isn’t much better than the flip of a coin.

“Some people,” Prof. Schoar says, “may have this almost blind belief that the manager at the top changes everything. Our results show that managers do matter, but they don’t change everything.”

Since the 1970s, several other studies have measured what happens when companies bring in new bosses. Most of the findings have been consistent: Changes in leadership account for roughly 10% of the variance in corporate profitability on average.
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a company will be much more inclined to replace the CEO after a run of bad losses—and to bring him in from a firm that has been on a hot streak. That leads to an illusion: “You change the CEO,” Dr. Kahneman says, “then performance reverts to the mean, and you attribute the improvement to the new guy.”

Furthermore, the hot profits at the new CEO’s former company are likely to cool off—by regression to the mean alone. When investors see that, they will mistakenly conclude that he is such a good boss that his old firm can’t thrive without him.