For decades, colleges and universities have pursued geographic diversity in their student bodies. Web pages proudly trumpet that this year the college has students “from all 50 states and from over 80 countries” (Harvard University) or that “the students come from throughout the United States and the world” (Stanford University). Even public universities use these formulations. At the University of Michigan in 2011, students came from “81 of 83 Michigan counties, all 50 states, and 54 countries.”
Nobody bats an eye at geographic diversity. What’s more, it seems to be on sound constitutional footing. Consider Texas’s Top 10 Percent program, which guarantees admission to a public college or university in the state to students who are in the top 10 percent of their graduating high school class. This program is properly understood as a form of geographical diversity, albeit finer-grained than in previous versions. It did not come in for criticism in Fisher v. University of Texas, the anti-affirmative-action lawsuit that the Supreme Court on Monday sent back to a lower court. Michigan’s attention to the number of counties from which it recruits students is a similarly fine-grained geographical approach, also without the controversy that has surrounded its other diversity initiatives.
There are good reasons why no one is bothered by geographic diversity. First, talent is everywhere, and excellence its magnet. The attraction of students from dispersed geographical origins toward any given campus itself proves that a campus’ offerings merit attention.
But a second reason to be enthusiastic about geographic diversity gets less discussion. Social scientists have long distinguished between “bonding ties,” which connect people who share similar backgrounds, and “bridging ties,” which link people who come from different social spaces. Since the 1970s, scholars have been aware that bridging ties are especially powerful for generating knowledge transmission; more recently, scholars have argued that teams and communities that emphasize bridging ties and learn how to communicate across their differences outperform more homogenous teams and communities in the development and deployment of useful knowledge. Historian Josiah Ober, for instance, makes a powerful case that the decision to organize ancient Athens by routinely bringing together citizens from urban, rural and coastal areas in teams for knowledge-generation and decision-making was a major source of that democracy’s strength. Geographic diversity is a sure way of maximizing the role of bridging ties in a campus community.
For this reason, I think it’s time to double-down on geographical diversity in college admissions. We should take it to the level of Zip codes and, in particular, to the level of the Zip+4 system. This Zip code system divides the United States into geographic units as small as a city block or group of apartments. Data management software is now sufficiently powerful that college admissions offices should easily be able to maximize Zip+4 diversity from within a pool of applicants whose credentials exceed that college’s entrance threshold. And given current residential patterns — with their extremely high degree of socioeconomic, racial, ethnic and ideological segregation, well-described in Bill Bishop’s book The Big Sort — geographic diversity at the level of Zip+4 will bring other sorts of valuable diversity along with it. This is all within the context of a very old and unproblematic tradition of geographical diversity.