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.

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.

Campaigns fail if they waste resources courting voters who are unpersuadable or already persuaded. Their most urgent task is to find and persuade the few voters who are genuinely undecided and the larger number who are favorably disposed but need a push to actually vote.

When Americans think of college these days, the first word that often comes to mind is 'debt.' And from 'debt' it's just a short hop to other unpleasant words, like 'payola,' 'kickback,' and 'bribery.'

From a social point of view, it's beneficial that homeownership encourages commitment to a given town or city. But, from an economic point of view, it's good for people to be able to leave places where there's less work and move to places where there's more.

What an economy really wants, after all, is not more investment per se but better investment. It wants capital to flow to companies that will create value - not in the form of a rising stock price but in the form of more goods for less cost, more jobs, and rising wages - by enhancing productivity.

Life insurance became popular only when insurance companies stopped emphasizing it as a good investment and sold it instead as a symbolic commitment by fathers to the future well-being of their families.