Social network guru Valdis Krebs has posted a new version of his classic illustration of political polarization in America, as viewed by the book-buying habits of Amazon's customers. Using Amazon's "also bought" data, he shows that the market for political books is clearly divided between "blue" and "red" book-buyers, with only a few titles crossing over to both audiences. Thus, buyers of "The Fall of the House of Bush" by Craig Unger were very likely to buy, say, Paul Krugman's "The Conscience of a Liberal," while readers of Glenn Beck's "An Inconvenient Book: Real Solutions to the World's Biggest Problems" also liked John Bolton's "Surrender Is Not an Option." Among the few "purple" crossovers: Lou Dobbs' "Independents Day." I've included a screen-shot of the network map, but Valdis has done something really cool and made the map interactive. You can click on a particular book, drag it around the screen and see how that re-arranges the network. This is 3-D journalism at its best.


In case that image of a polarized America depresses you, don't worry, it's just a picture of how the tiny number of people who buy books vote with their pocketbooks. And we shouldn't be surprised to find that highly-attentive people who buy political books are a highly opinionated group. The rest of the country is clearly much more impressionable. Valdis points to a fascinating piece from Monday's Washington Post by Shankar Vedantam that reports on a study examining the role social networks play in influencing our choices from entertainment to politics. Vedantam writes: "when large networks of people evaluate something together -- and it does not matter whether we are talking about songs or 'American Idol' contestants or presidential candidates -- their conclusions are not only powerfully shaped by the views of others, but by the network that binds them together."

Um, I think this is why so many activists play such close attention to the power of the mainstream media, as it is still the primary network that "binds" us together around elections. And it's why some of us are cautiously optimistic about the rise of the "networked public sphere" as a better system for filtering important information into the consciousness of the public.

But Vedantam has sobering news for everyone who is obsessing about every detail of the election currently underway:

Quality matters, but when voters intensely watch one another, the success of candidates depends at least as much on network dynamics as it does on the quality of the candidates themselves. Because network dynamics are not governed by intuitively simple rules of cause and effect -- depending on where they are in a network, people with strong opinions might end up with little influence, while the weak opinions of others get greatly magnified -- networks regularly produce outcomes that are partly arbitrary....The decisive factor, they show in a series of mathematical models, is not the presence of influential people but people who are easily influenced. Random, insignificant events are vastly magnified by networks of such malleable people influencing one another, and this tilts the race one way or another. Blind chance plays a big role.

And you thought former President Bill Clinton was kidding when he argued that voting for Barack Obama might be akin to a roll of the dice! Maybe every election is a roll of the dice--or it's time for us to think about smarter ways to manage government?