In the top ten on Digg’s “World & Business” section today is an item titled “Visual Validations of the 50 State Electoral Strategy” that links to a University of Michigan page with some fascinating cartograms. The digger and the author of the Michigan site make the point that each state is hardly of a red or blue state, but rather a mosaic of purples communities. We couldn’t agree more.
Digg links to cartograms of the 2004 presidential election, but I think the 2006 congressional elections page is more interesting. Here are some maps from that page, including a abridged version of the points that the author of the site is trying to make.
House of Representatives Electoral Map
The map is a sea of red, but we know that Democrats won the House. So take a look at the various population densities in each district.
Population Density
If you combine the electoral map with the population density one, you get a cartograph. Each district is scaled to population, regardless of their actual area on the ground.
House Cartogram (Districts scaled by population)
In theory each district is supposed to have a roughly number of constituents. Here’s a cartograph where each district is scaled to an equal size.
House Cartogram (Districts are equal size)
Jeremy
24 March 2008 at 1:34 pm
Nice post. Just a small nitpick: these maps are known as cartograms not cartographs.
Patrick Ottenhoff
24 March 2008 at 1:36 pm
Thanks Jeremy. I should have known that. Guess I’m working at Monday-speed today.
Cartophiliac
24 March 2008 at 2:31 pm
That UMich site is one of my favorites. It was one of my inspirations to look deeper into maps and how we use and misuse maps to present information, or as Monmonier says, “How To Lie With Maps.”
I think the most telling map from that site is when Newman breaks down the 2004 electoral cartogram by county, then shades them by how strongly each county voted red or blue. The result is that after the 2004 election, the US was just a big bruise.
http://www-personal.umich.edu/~mejn/election/countycartlinearlarge.png