The stock market has an insidious effect on C.E.O.s' moods, because of its impact not just on their companies but on their own bank accounts.

A general principle of good taxation is that similar jobs, and similar kinds of compensation, should be taxed the same way: otherwise, the government is effectively subsidizing some jobs over others.

Meeting external deadlines is much harder than meeting internal ones. On the other hand, internal deadlines sometimes don't feel real, and are therefore easy to evade.

The autocracies of the Arab world have been as economically destructive as they've been politically repressive.

Behavioral economists have shown that a sizable percentage of people are willing to pay real money to punish people who are taking from a common pot but not contributing to it. Just to insure that shirkers get what they deserve, we are prepared to make ourselves poorer.

Political risk is hard to manage because so much comes down to the personal choices of policymakers, whether prime ministers or heads of central banks.

Intellectual-property rules are clearly necessary to spur innovation: if every invention could be stolen, or every new drug immediately copied, few people would invest in innovation. But too much protection can strangle competition and can limit what economists call 'incremental innovation' - innovations that build, in some way, on others.