There are fashions in building. Behind the fashions lie economic and technological reasons, and these fashions exclude all but a few genuinely different possibilities in city dwelling construction at any one time.

[Cities] are not like suburbs, only denser. They differ from towns and suburbs in basic ways, and one of these is that cities are, by definition, full of strangers.

There are two ways you encounter things in the world that are different. One is everything that comes in reinforces what you already believe and everything that you know. The other thing is that you stay flexible enough or curious enough and maybe unsure of yourself enough, or may be you are more sure of yourself - I don't know which it is - that the new things that come in keep reforming your world view.

observation of realities has never, to put it mildly, been one of the strengths of economic development theory.

All my life I have been hearing that the oil was going to run out. It never happens. They keep discovering new oil fields. The world is apparently floating in oil fields.

To seek "causes" of poverty in this way is to enter an intellectual dead end because poverty has no causes. Only prosperity has causes.

In trading with each other cities can't be in too different stages of development, and they can't copy one another. Backward cities, or younger cities, or newly forming cities in supply regions, have to develop to a great extent on one another's shoulders. This is one of the terrible things about empires. Empires want them only to trade with the empire, which doesn't help them at all. It's just a way of exploiting them.