The samples of 21 presidents overall and the five with private-sector experience are far too small to draw firm conclusions. But the review suggests, at minimum, that private-sector business experience is neither a great predictor of presidential success nor — given the success of many presidents with no private-sector experience — a prerequisite for presidential success.

Moreover, even a rudimentary analysis of history and politics suggests that success in public leadership may require a very different set of skills than that required in private-sector leadership.

Private-sector executives have a much clearer measuring stick that can define direction and success: specifically, a bottom line, defined in terms of growth and/or profit. For presidents, goal-setting and definitions of success are more complex, more likely to change over time and, given much greater levels of subjectivity, harder to assess. In their non-bottom-line world, perception can sometimes be almost as important as reality…

Most important, executives in the private sector have more power to command and, in a way, far more authority to get what they want done. Presidents, as political scientist Richard Neustadt cogently explained years ago, must rely more on persuasion than command. American governmental structures and processes put too much power in too many places — much of it shared — to enable command to get a president very far. Success in the presidency relies more on the ability to persuade, negotiate and compromise, and to do so in both public and private arenas and with inside- and outside-the-Beltway constituencies, including the public.