Thursday, September 22, 2011

Pretty Maps

This week, my happiness about Elizabeth Warren running for Senate in Massachusetts...

(transcript here)

...combined with this (funny? offensive? certainly clever, certainly reductive) t-shirt for sale at Threadless Tees...

(click on it to enbiggen; you can buy it here)

...combined with my recent perusal of maps because I'm going on vacation next week to a part of the country I barely know at all...

(no picture for that one, sorry -- though maybe there will be once I get back!)

... all got me searching the internets for something I'd remembered seeing once before. I found it. It was created by Mark Newman in the Department of Physics and the Center for the Study of Complex Systems at the University of Michigan. Here it is:

What is that purple monstrosity?

Well, many of you will recognize this:

It's the results of a USA presidential election (in this case, 2008). Blue is for Democrat, red is for Republican; each state is colored either red or blue to represent which party the majority of voters in that state voted for. The winner on a state-by-state basis matters, completely, because of our weird electoral college system.

And perhaps some of you will recognize this:

Two new things are going on in this map. First, the map is divided into counties, rather than states, to better show variations within any given state. Second, rather than straight red (Republican) or straight blue (Democratic), most areas on the map are a shade of purple, representing percentages of voters in any given county voting for either party.

Doesn't this feel like a more accurate representation of voter behavior than the straight red state/blue state map? There is a LOT of purple on this map. Of course, we elect the president via state results, not county results, and populations vary from county to county, so it has no direct relevance to the results. But if you've been a blue voter in a red state or a red voter in a blue state, this map definitely represents you better than the straight red and blue map.

But there is still one enormously relevant thing it fails to represent! Returning to the purple monstrosity:

This map is called a cartogram. It's a map which shows the relative size of counties by population, rather than by area. That's why everything seems distorted. On this map, Rhode Island takes up twice as much space as Wyoming, even though in area, Wyoming is sixty times bigger than Rhode Island -- because Rhode Island has more than twice as many people than Wyoming.

There are hardly any plain red (Republican) spots on this map at all. There are some places that look plain blue (Democratic) -- mostly the big cities.

See how mixed-up and evenly divided we, and our opinions, are? See the political diversity of our neighbors? I'd like to get that on a t-shirt!

Here's where I found all these maps, plus more maps I didn't show, and all the explanations. All maps are © 2008 M. E. J. Newman. Thanks to Professor Newman for allowing the free distribution of his text and images. Go check out the webpage, it's interesting stuff.

And thanks to JL for links.