Consider one of the greatest businesses in the world after decades of mismanagement. Growth is tepid, at best, and has been fuelled largely by debt. The organisation’s systems and infrastructure are outdated. International competitors have taken advantage of its weak position and stolen market share. A proxy contest is looming. The chief executive is about to step down, and the board and shareholders are faced with a decision about leadership. Who should they appoint? What qualities should they seek?

A turnround requires a leader with exemplary character, intelligence and independence, with a demonstrated record of success. It needs someone who can recruit extraordinary people, who understands the details yet knows how to delegate, negotiate and compromise. In short, a leader who commands respect from employees, the board and the shareholders.

After 9/11, New York needed such a leader. When Michael Bloomberg was sworn in as mayor on January 1 2002, the city was burning — literally. Our economy had crashed and public finances were shot. New Yorkers were scared and depressed.