Cicero, Patti Smith, and Agglomeration Economies

A reminder on how cities can enrich and inspire you

Yesterday I happened to read two paragraphs from two wildly different sources, places and times. However, there was an interesting connection between them.

The first was the opening paragraph of Marcus Tullius Cicero’s On Duties, Cicero’s treatise on moral obligations (completed shortly before his assassination). On Duties is framed as a long letter, or a handbook, to Cicero’s son Marcus, who was studying philosophy in Athens. Here’s how it begins (in the translation of Walter Miller for Loeb):

My dear son Marcus, you have now been studying a full year under Cratippus, and that too in Athens, and you should be fully equipped with the practical precepts and the principles of philosophy; so much at least one might expect from the pre-eminence not only of your teacher but also of the city; the former is able to enrich you with learning, the latter to supply you with models.

Cicero thinks that his son must have learned a lot after a year in Greece, for two distinct reasons. The first is that he’s studying with Cratippus, a leading philosopher of the time, much admired by Cicero. The second reason is that Marcus is staying in Athens.

In the 1st century BCE, Athens was no longer an independent power. It had been eclipsed militarily and politically first by the Hellenistic kingdoms and then by Rome. But it remained a premier center for philosophy and education. Throughout the Hellenistic period Athens had been the leading center for philosophical study. In the Roman period its philosophers held Rome-endowed chairs, and schools of philosophy and rhetoric continued to flourish for centuries.

Why is living in Athens, according to Cicero, a great way to learn? Because Athens, as a city with a lot of smart and interesting people, teaches by example.

Cicero says: Your teacher can enrich you by means of knowledge (scientia); the city can enrich you by means of examples or models (exemplis). In other words, Cicero thinks that his son had surely met so many interesting people, and listened to interesting conversations, and seen interesting people in action. That by itself is a great way of improving oneself.

The second paragraph I stumbled upon, a few hours after reading Cicero, is from Ezra Klein’s interview of Patti Smith, quoted by Scott Sumner in his Substack, where Smith talks about the Greenwich Village of the 1960s:

When I was working at Scribner’s, I waited on Larry Rivers, I waited on Robert Rauschenberg, I delivered books to the building where Mark Rothko lived and saw him on the elevator.

You saw these people. They were there. You knew where their studios were. Jimi Hendrix’s studio was across the street from where Lee Krasner and Jackson Pollock painted. Art was everywhere. Andy Warhol ate in the same restaurants as we did. We all comingled more.

Smith is talking about the very same thing Cicero was talking about. Great cities can enrich and inspire you because they attract a lot of interesting people and being closely exposed to so many interesting people has an effect on your thoughts, creativity, ideas, ways of life.

Economists have a name for this phenomenon: agglomeration economies. Here’s how Ed Glaeser explains it (Agglomeration Economics (2010) p.9):

The core idea at the center of information-based agglomeration economies is that all of our knowledge builds on things that we learn from people around us. The central premise is that the presence of knowledgeable neighbors enables an apprentice steelworker to learn his craft, but it also makes a biotechnology researcher more innovative. The interaction of smart people in urban areas both enhances the development of person-specific human capital and increases the rate at which new ideas are formed.

The basic idea goes back at least to Alfred Marshall, one of the fathers of modern economics (Principles of Economics (1890) p. :

Great are the advantages which people following the same skilled trade get from near neighborhood to one another. The mysteries of the trade become no mysteries: but are as it were, in the air, and children learn many of them unconsciously.

Here’s Ed Glaeser again explaining a model that formalizes Marshall’s theory (Learning in Cities, 46 J. of Urban Econ. 254, 256 (1999)):

The model in this paper focuses on faster human capital accumulation in cities as a result of learning through imitation. The number of contacts per period rises with city size and the speed of learning rises with the number of contacts. Of course, cities may provide an opportunity for learning beyond the ability to copy the more skilled. While rural areas may contain only a narrow range of experiences, urban areas may contain a plethora of experiences which build skills. Cities may facilitate the division of labor which enables individuals to specialize in a particular range of skills and therefore become more productive more quickly… Finally, the scale economies afforded by urban areas may allow better schools to be built in big cities and therefore facilitate formal education.

Just as Cicero said: science and examples.