Archive for September, 2009|Monthly archive page

Sorting through The Big Sort

The Big Sort
Maybe I spent too many years living in the same county as the authors, but I agree with everything Bill Bishop and Robert Cushing have written in their book The Big Sort: Why the Clustering of Like-Minded America Is Tearing Us Apart.

My only problem with this book is that it is, well, a book. While the narrative is quite readable, most of the trends probably aren’t that surprising to most readers. What would likely surprise many readers though, is how such small changes in human behavior can cause such large changes in the cultural landscape. This is difficult to communicate in a text narrative. Models are better suited for this.

There is a Big Sort website, and it even has some maps. But the website is primarily geared towards selling the book. The authors have obviously collected a lot of data regarding cultural changes over the past 50 years, why not publish that too? That way, animated maps showing historic trends, plus agent based models could be developed.

The models would let readers users make small changes to agent behaviors and watch how those changes impact settlement patterns through time.

Agent based modeling has been applied to Nobel laureate Thomas Schelling’s game theory of how racial segregation occurs.

Allen Downing has written a free online computational modeling textbook, where he points out that Schelling’s model implies that “if you observe segregation in a real city, you cannot conclude that the people in the city are racists”.

Something that was new to me in The Big Sort was the research describing how the views held by a group of people become more extreme through time – more extreme than the average of the individuals in the group. This suggests that, for example, while people may not be motivated by racism to move, living in a segregated neighborhoods might slowly cause them to become racist. This too could be modeled, by having degrees of red or blue, based on how long an agent has been surrounded by similar colors.

Downing includes this exercise:

The mechanism Bishop hypothesizes is not that people, like the agents in Schelling’s model, are more likely to move if they are isolated, but that when they move for any reason, they are likely to choose a neighborhood with people like themselves. Modify your implementation of Schelling’s model to simulate this kind of behavior and see if it yields similar degrees of segregation.

If Bishop & Cushing would publish their data on their website, students working on this exercise would be able to publish models demonstrating the processes described in the book.

Who knows, maybe even the real estate listing sites might start including a scaled index to guide buyers who are consciously searching for a diversified neighborhood.

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