This week’s column is drawn from a lecture I gave earlier this year at the University of Southern California on the occasion of the retirement of urban economist Peter Gordon.

One of my heroes is the urbanist Jane Jacobs, who taught me to appreciate the importance for entrepreneurial development of how public spaces—places where you expect to encounter strangers—are designed. And I learned from her that the more precise and comprehensive your image of a city is, the less likely that the place you’re imagining really is a city.

Jacobs grasped as well as any Austrian economist that complex social orders such as cities aren’t deliberately created and that they can’t be. They arise largely unplanned from the interaction of many people and many minds. In much the same way that Ludwig von Mises and F. A. Hayek understood the limits of government planning and design in the macroeconomy, Jacobs understood the limits of government planning and the design of public spaces for a living city, and that if governments ignore those limits, bad consequences will follow.

Planning as taxidermy

Austrians use the term “spontaneous order” to describe the complex patterns of social interaction that arise unplanned when many minds interact. Examples of spontaneous order include markets, money, language, culture, and living cities great and small. In her The Economy of Cities, Jacobs defines a living city as “a settlement that generates its economic growth from its own local economy.” Living cities are hotbeds of creativity and they drive economic development.

There is a phrase she uses in her great work, The Life and Death of Great American Cities, that captures her attitude: “A city cannot be a work of art.” As she goes on to explain:

Artists, whatever their medium, make selections from the abounding materials of life, and organize these selections into works that are under the control of the artist . . . the essence of the process is disciplined, highly discriminatory selectivity from life. In relation to the inclusiveness and the literally endless intricacy of life, art is arbitrary, symbolic and abstracted. . . . To approach a city, or even a city neighborhood, as if it were a larger architectural problem, capable of being given order by converting it into a disciplined work of art, is to make the mistake of attempting to substitute art for life. The results of such profound confusion between art and life are neither art nor life. They are taxidermy.

So the problem confronting an urban planner, and indeed government planning of any sort, is how to avoid draining the life out of the thing you’re trying to control.

The trade-off between planning and complexity

Viewing cities as spontaneous orders and not as works of art helps to explain the trade-off between scale and order. In general, I believe the larger the scale of a project, the fewer the discoveries and subtle connections the people who use that space will be able to make.

Placing an apartment building in a commercial block will change the character of that block in unpredictable ways, but the surrounding urban environment can usually absorb the repercussions and the problems are relatively small. A block-sized mall, however, constrains much further how people can use that space and has a disproportionately larger impact on the neighborhood. And a mega-project that takes up many blocks severely limits the diversity and range of the social connections, as it challenges the planner to substitute her genius for the genius of many ordinary people using their own local knowledge to solve problems only they may be aware of. Making something bigger increasingly limits what people can do and whom they can bump into in the space that it occupies. Scaling up narrows the range of the informal contacts that drive creativity and discovery.

And for a given size or scale of a project, the more the planner tries to predetermine the kind of activities the people who use it can do in it, the less likely that her design will complement the spontaneous contact that generates and diffuses new ideas. That’s what made a lot of traditional downtowns so important. Over time the combination of diverse uses of public space (in the sense I mean here) brought people with different skills and tastes together in large numbers. Design can of course complement that informal contact to a point, but beyond a fairly low level, human design begins to substitute for it.

Of course, small is not always beautiful, and big is sometimes unavoidable. But that makes it even more important that planners appreciate how ramping up scale and intensifying design influences a complex social order.

Private planning is much more limited in scale

And I’m not just talking about government projects. Private projects could, in principle, have the same “taxidermic” impact on urban vitality. But as long as a planner’s design is small compared to the surrounding space, the loss of complexity and intricacy isn’t severe. It’s usually when government somehow subsidizes private projects, softening up the budget constraint, that the scale becomes massive and the downside very steep. An example of this can be found about a mile from where I live in New York. Barclays Center, the new home of the NBA’s Brooklyn Nets, grew to an enormous size once the local and state governments offered eminent domain and other large subsidies. Building on a massive scale in an already dense urban environment is typically too expensive, even for a wealthy private developer, without such legal privileges.

A planner can’t build an entire city (or neighborhood even) because she can’t begin to design and construct the necessary diversity and social intricacy that happens spontaneously in a living city. And I don’t think she should even try to because it can irreparably damage, even kill, the living flesh of a city. What can government do? In the ordinary course of its activities a government can perhaps at best refrain from doing the things that would thwart the emergence of the invisible social infrastructure that gives rise to that diversity, development, and genuine liveliness.

The rest is mostly taxidermy.