When does self-deception do the most good?

Knowledge@Wharton: In your chapter, "The Dangerous and Necessary Art of Self-Deception," you write that some degree of optimistic self-deception is critical for success, and that "depressive realists," with their more accurate view of the world, fall behind. What advice would you give to a board choosing a CEO? Is it better to have an optimistic self-deceiver or a depressive realist?

Cowen: For a CEO, I'd tend to go for the realist, because at the leadership level, the costs of hubris are very high. The problem with realists is they can get depressed and feel they are not going anywhere, but this is less likely to happen to CEOs, because they are in charge.

In the lower rungs of the company, however, I would favor overly optimistic people, those who are motivated by the idea that they always have a chance of being promoted or earning more money. The higher up you are, the more I would prefer realism. A president who won't listen can be pretty disastrous. But a senator who doesn't listen -- maybe it's not ideal, but there are checks and balances, and if the optimism gets the senator to work harder, then that is the compensation.

Here is the full interview with me.  By the way here is a recent Indian review of Inner Economist, from Mint.