How to Lie with Maps


When I was in school I took a lot of Geography courses. One of my textbooks was How to Lie with Maps by Mark Monmonier. A very interesting book. The basic concept is that it is impossible to represent a round surface on a flat one without distorting something. Remember how when you look at a map of the world and Greenland looks to be almost as big as the entire continental US? It isn’t really that big. Look at a globe and you can see the difference.

The reason this happens is because in order to make most of the continents look like they actually look, map makers stretch out the land masses in the polar regions. The only area on the map (to the left) where scale and distance is exactly correct is at the equator. The further North or South you go the more distorted everything gets. This is just one way that they can distort maps.

For most people this doesn’t matter. Most people live in the regions that look mostly correct. I bet it you meet someone from Greenland and you ask them how they feel about their county being grossly misrepresented on maps, they will have something to say about it.

This even happens on smaller scale maps. A map of Montana for instance. The following two maps were distorted differently with the math used to create them. One tries to preserve the curved perspective of the latitudinal lines as seen on the actual curved Earth. The other map ignores this so that it can show the East/West lines as straight.

Now you ask how is this lying? Well, it is distorting the representation of the Earth because it has to. Think about it a different way though. All maps have a purpose: road maps, naval navagational maps, topographical maps, political leanings, climatic maps, weather maps, underground cave maps, etc. If you are looking at a road map for the state of Montana, are the roads actually as big as the lines drawn on the map? Of course not! Are the towns only as big as the dots used to represent them? Do the forests of parks begin and end exactly where the lines make them? When a river runs right next to a road they might move it a bit on the map so that it can easily be seen and differentiated. The maker of the map has to choose what is important and what isn’t or else a map would get way to cluttered with information to be of any use.

These two maps use slighty different data but they do show two very different ways of looking at the US political trends. Area vs. Electoral Votes. One map looks fairly even and the other leans towards the blue.

Here is an interesting article from the BBC about maps.

A good map delivers concise information in a very clear way for a specific purpose. That purpose is decided by the creator of the map.

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2 Responses to “How to Lie with Maps”

  1. Regarding the Electoral Votes map . . .

    The National Popular Vote bill would guarantee the Presidency to the candidate who receives the most popular votes in all 50 states (and DC).

    Every vote, everywhere, would be politically relevant and equal in presidential elections. Candidates would need to care about voters across the nation, not just undecided voters in a handful of swing states.

    The bill would take effect only when enacted, in identical form, by states possessing a majority of the electoral votes–that is, enough electoral votes to elect a President (270 of 538). When the bill comes into effect, all the electoral votes from those states would be awarded to the presidential candidate who receives the most popular votes in all 50 states (and DC).

    The bill uses the power given to each state by the Founding Fathers in the Constitution to change how they award their electoral votes for president.

    In Gallup polls since 1944, only about 20% of the public has supported the current system of awarding all of a state’s electoral votes to the presidential candidate who receives the most votes in each separate state (with about 70% opposed and about 10% undecided). The recent Washington Post, Kaiser Family Foundation, and Harvard University poll shows 72% support for direct nationwide election of the President. Support for a national popular vote is strong in every state, every partisan group, and virtually every demographic group surveyed in recent polls in closely divided battleground states: Colorado– 68%, Iowa –75%, Michigan– 73%, Missouri– 70%, New Hampshire– 69%, Nevada– 72%, New Mexico– 76%, North Carolina– 74%, Ohio– 70%, Pennsylvania — 78%, Virginia — 74%, and Wisconsin — 71%; in smaller states (3 to 5 electoral votes): Alaska — 70%, DC — 76%, Delaware –75%, Maine — 77%, Nebraska — 74%, New Hampshire –69%, Nevada — 72%, New Mexico — 76%, Rhode Island — 74%, and Vermont — 75%; in Southern and border states: Arkansas –80%, Kentucky — 80%, Mississippi –77%, Missouri — 70%, North Carolina — 74%, and Virginia — 74%; and in other states polled: California — 70%, Connecticut — 74% , Massachusetts — 73%, Minnesota — 75%, New York — 79%, Washington — 77%, and West Virginia- 81%.

    The National Popular Vote bill has passed 29 state legislative chambers, in 19 small, medium-small, medium, and large states, including one house in Arkansas, Connecticut, Delaware, Maine, Michigan, Nevada, New Mexico, North Carolina, and Oregon, and both houses in California, Colorado, Hawaii, Illinois, New Jersey, Maryland, Massachusetts, Rhode Island, Vermont, and Washington. The bill has been enacted by Hawaii, Illinois, New Jersey, Maryland, and Washington. These five states possess 61 electoral votes — 23% of the 270 necessary to bring the law into effect.

    See http://www.NationalPopularVote.com

  2. […] context to this post see the “How to Lie with Maps” post. One of these maps is most interested in representing geographical area and the other […]

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