In a recent post on the Economix blog, Edward Glaeser discusses the challenges of population density in big cities. Proximity to millions of people means more sharing of ideas, greater cultural amenities, a wider variety of goods and services, and more diverse job opportunities. It can also mean greater exposure to crime, congestion, pollution, disease, and violence. Keeping the costs of proximity in check sometimes requires stronger and more intrusive government than people in less densely populated areas are used to.
“I’m a big fan of the free market, and I see lots to like in liberty. But the downsides of proximity, be they cholera or crime, have never been solved with laissez-faire. Costly, often intrusive public action has often been needed to manage the negative externalities associated with urban density.”
Glaeser notes that large investments in street cleaning and public waterworks reduced urban disease in cities like New York and Philadelphia. In addition to lowering peoples’ exposure to easily preventable illness, clean streets and water make cities more pleasant places for each resident. The total cost of these types of projects is very high, but in cities with millions of people the cost per person is quite low.
His broader point, that densely populated urban areas require stronger government, applies to other urban ills as well. Greater vulnerability to crime and violence may make urban residents more tolerant of surveillance cameras and restrictive gun laws than their rural and suburban counterparts. To reduce pollution and congestion, cities may invest large sums in public transit, impose strict emissions standards, or implement schemes like congestion pricing or dynamic pricing for parking spaces — policies that may not be necessary in sparsely populated areas.
We tend to assume that those who are free to choose will choose fewer restrictions, but large cities illustrate that such choices are more complex. People may choose to live in cities with restrictive laws and stronger, more intrusive government to avoid the costs of urban density while enjoying its benefits. The challenge for lawmakers at the national level is to create a flexible framework that maintains fundamental rights but allows for differences between the rules adopted in densely and sparsely populated areas.