They say a lie can travel around the world in the time it takes for the truth to get its boots on. Richard Carson's "Bowling Alone in Urbanistaville" recently published on the website ArchNewsNow repeats false statements about a study that compares social activity in the suburbs and the city. "The statistical revelation behind all of these findings is that for every 10% increase in density, there is a 10% decrease in socialization. That's a simple, one-to-one inverse relationship that everyone can understand," he writes.
That's not even close to being true - as Carson would know if he read the study. "Social Interaction and Urban Sprawl," by Jan Brueckner and Ann Largey, finds that people talk to their neighbors and hang out with friends more in cities than in suburbs on a per capita basis. They found no statistically significant difference in other observed social activity, such as the number of friends and confidants, based on density.
To fully explore how that simple truth got twisted 180 degrees, we have to look more deeply at the study, its methods, its presentation, and how the authors publicized the findings.
The 'Unobservable' Tendency
Brueckner and Largey use an instrumental-variables (IV) estimation to put numbers on what they call an "unobservable propensity," the tendency of gregarious people to locate in cities. IV estimation is used to correct for what the authors assume is the self-selection bias of people who want to live close to their neighbors.
How do the authors know that something that they can't detect actually exists and can be measured? They don't. They assume that a normal person would seek to maximize lot size - that is, locate in a suburban place - all things being equal. Gregarious people, they say, like living closer to their neighbors and are willing to sacrifice lot size in proportion to their desire to be social.
In the authors' view, this would create higher social activity in cities, and so the authors sought to take out the bias - that is, weight the results according to the tendency of outgoing people to live in denser environments. The entire credibility of the study depends upon that assumption, which, as they say, is based on something that is "unobservable."
Without the IV estimation, the study results are, as I have stated earlier, slightly in favor of cities. With the IV estimation, Brueckner and Largey find an advantage for suburbs - but you have to go from very high density (11,591 people per square mile) to very low-density (779 people per square mile) to see any appreciable effect. This 93 percent drop in density increases the chance of talking with neighbors by 5 percent, hanging out with friends by 7 percent, and having friends over to your house by 13 percent. Why use such an extreme drop in density? That's because a less dramatic drop - say, 10 or 20 percent - yields numbers that are not statistically significant.
So much for the study and its methods, but its presentation and publicity is even stranger. Brueckner and Largey bury the straightforward, non-IV results of their study. They weren't in the press release or the introduction. Rather, you have to read deep into a paper full of barely readable jargon, comparing statements with tables not designed to enhance clarity. Here's a sample of the authors' prose: "As can be seen, the density coefficients are insignificant in the non-IV case in the NEISOC, CONFIDE, FRIENDS, FRNDHOM equations, becoming significantly negative when IV estimation is used. By contrast, the non-IV coefficients are significantly positive in the NEITALK and FRNDHNG equations, while IV estimation leads to coefficients that are negative and insignificant." These acronyms refer to social activity measures, and what the two sentences mean is that the assumption that gregarious people live in cities reverses the observed findings of the study. The authors then claim that the findings support the assumption - an example of circular logic if I ever saw one.
If the writing and logic were bad, the publicity was even worse. University of California Irvine, where Brueckner is an economics professor, reported in a press release the figures that Carson repeated - that a 10 percent decrease in density yields a 10 percent increase in social activity. Brueckner told me in an email dated January 1, 2007, more than a year and a half ago, that the error was a miscalculation made under deadline pressure, but that nothing could be done to correct it. The false press release figures remained on the UC Irvine website until July of this year, when I complained directly to the publicity department after seeing Carson's essay.
This all adds up to a pattern of mendacity - perhaps by a professor with a pro-sprawl agenda, perhaps by one seeking publicity, perhaps both - yet the twisted and exaggerated results of this dubious study have been reported by various news organizations that were more willing to pull material off of a press release than to dig deep into gobbledygook.
The Choices of the Gregarious
All of that only scratches the surface of what's wrong with this study. The idea that complex urban development patterns and human behavior can be meaningfully studied according to one primary criteria - density - is wrong from the start. There's good density and bad density from the standpoint of how humans act and interact. Consider a walkable, mixed-use, but primarily single-family urban neighborhood compared to an apartment complex surrounded by surface parking off of an eight-lane arterial. The latter is higher density but the former is more likely to attract people who want to get to know their neighbors. Urban public spaces can be designed to be inviting, comfortable, and even inspiring - an approach that helps to bring diverse people out of the private realm into contact with one another.
People choose different environments - some dense, some less dense - at various time in their lives as their needs change, for reasons too numerous to mention. It doesn't mean that they have become more or less gregarious.
Brueckner and Largey conclude that someone who is looking for a richer social life would do better to move to a cul-de-sac on a one- to two-acre lot. That cul-de-sac is populated by introverts, according to their own formula. That's a parody of social science at its most ridiculous.
But it works for Carson, whose favored term for urban planners, "urbanistas," is a takeoff on Sandinistas, a cheap attempt at red-baiting. A true-blue defender of sprawl, Carson is willing to take any nonsense and run with it.
Robert Steuteville is editor, publisher, and founder of New Urban News, the newsletter covering the New Urbanism and smart growth. He is president of New Urban News Publications - providing news, ideas, and connections for New Urbanism - which has played a leading role in this trend for more than a decade.