The Washington Post: What are "Super Zips" and why are so many clustered around Washington DC?

According to the article, Super Zips are the zip codes which have a high percentage of residents with education and high income. Washington D.C. have many Super Zips, and the feature is many of these cluster around there.

The mechanism of this phenomenon isn’t complex. First, the rich people who “want to be in a place that has an atmosphere of intellectual curiosity” comes to the metropolitan area. On one hand, others who have lived there for a long time cannot pay the rent and they have to leave for outside because the prices of the lands got higher due to the increased demand. Therefore this leads to the repeating process of the wealthy population to swarm in the metropolitan area and the rest to live around them.

The reporter says this phenomenon causes the economically bipolarization. I think it’s dangerous for the American economy to lost middle-income class which plays an important role in Economic growth.


http://www.washingtonpost.com/sf/local/2013/11/09/washington-a-world-apart/