A lot of people have blamed short-term thinking for causing our current economic troubles, which has set off a debate about what time window we should use to assess a CEO’s performance. Today boards of directors, senior managers, and investors intensely want to know how CEOs handle the ups and downs of running businesses over an extended period. Many executive compensation plans define the “long term” as a three-year horizon, but the real test of a CEO’s leadership has to be how the company does over his or her full tenure.

A version of this article appeared in the January–February 2010 issue of Harvard Business Review.