THE PROBLEM

Nissan followed other global carmakers last week in delivering worse results than it had predicted. In spite of it remaining one of the most profitable companies in the sector, it failed to achieve the targets set by Carlos Ghosn, reigniting debate among some analysts about whether he is overstretched as chief executive of both Renault and Nissan, a dual role he has held since 2005. How should one judge the appropriate limits of a CEO’s responsibilities? At what point does a job become too big for one person to handle? And is the risk of overstretch outweighed by the benefits of having a proven manager in control?