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How Blue Is My Country?

How Blue is My Country?

My father sent along a link with the following annotation:

We all know the expression that “one picture is worth a thousand words.” Well, here are several pictures of the same phenomena that tell the same story but give very different impressions. They illustrate clearly how pictures can be misleading (or should that be ‘leading’ ?). I found them very interesting. Please look at all of them.

The link lead to a web page by Michael Gastner, Cosma Shalizi, and Mark Newman of the University of Michigan offering Maps and cartograms of the 2004 US presidential election results. Their page takes issue with the typical map that shows red and blue states by geographic area.

The (contiguous 48) states of the country are colored red or blue to indicate whether a majority of their voters voted for the Republican candidate (George W. Bush) or the Democratic candidate (John F. Kerry) respectively. The map gives the superficial impression that the “red states” dominate the country, since they cover far more area than the blue ones. However, as pointed out by many others, this is misleading because it fails to take into account the fact that most of the red states have small populations, whereas most of the blue states have large ones. The blue may be small in area, but they are large in terms of numbers of people, which is what matters in an election.

We can correct for this by making use of a cartogram, a map in which the sizes of states have been rescaled according to their population. That is, states are drawn with a size proportional not to their sheer topographic acreage — which has little to do with politics — but to the number of their inhabitants, states with more people appearing larger than states with fewer, regardless of their actual area on the ground. Thus, on such a map, the state of Rhode Island, with its 1.1 million inhabitants, would appear about twice the size of Wyoming, which has half a million, even though Wyoming has 60 times the acreage of Rhode Island.

Cartograms look funny, but they solve a real problem: Democracy is, theoretically, about people, not money or land.

Gastner, Shalizi, and Newman have put together a variety of maps that show breakdowns by state and county, shaped according to goeography and population, and colored by in solids and shades. Their final result is a cartogram that shows a country not quite as divided as it seemed in the earlier maps.