Get Yourself A Great Mouser

If nations aren’t the best unit to analyze the economy, what is? This is a Jane Jacobs book, so the answer is obviously going to be cities.

Jacobs doesn’t actually give a clear argument why. Maybe that was in her previous book, The Economy of Cities. So far as I can see, her reasoning is, ironically, a bit tautological: “all developing economic life depends on city economies; it depends on them by definition because, wherever economic life is developing, the very process itself creates cities and has probably always done so.”

But so far as I can see, this reasoning is correct. Cities concentrate people, and therefore economic life, and therefore economic power. The driving force for all this is a phenomenon that, from what I gather, was discovered by Jacobs when she wrote The Economy of Cities: import replacement.

Consider, say, Boston back when it was a tiny settlement, not yet a city, in colonial times. At first, Boston didn’t produce much, especially not much that would be of interest to its main trading partner, London. It exported some natural resources: timber, fish. Whatever else the Bostonians needed, they needed to import it from other cities, again mostly London. (Remember to think of imports and exports in terms of cities, not nations.) For instance, at first, all metal tools in Boston came from European cities, and were paid for by the revenue from selling the timber and fish.
Then, one day, some Bostonians decided to build an ironworks and make metal tools themselves. (Pictured: a reconstruction of the Saugus Iron Works, established 1646.)

This wasn’t of any interest to London or other European cities. The Bostonians weren’t nearly as good or efficient at making metal tools as Londonians were. So Boston couldn’t export the metal tools back to Europe — but it could use them internally, and also export them to other American cities that were about as poor as Boston was, or poorer. Internally, this meant the spark of a manufacturing economy in Boston, as easily obtained metal parts made it easier for other Bostonians to replace other imports from European cities, and eventually develop a symbiotic network of industries. It also meant that the revenue from fish and timber could be used to import new things, including new innovations from European cities (which would later become opportunities for more import replacement). And because there were customers for Boston-made metal goods in New York and Philadelphia, and eventually Cincinnati and Chicago and Pittsburgh as these cities came into existence, it meant additional revenue for Boston that it could reinvest into developing its production further.