A study performed by two grad students at Northwestern University reveals the patterns of human mobility, the movement of people, within the United States. The study was conducted by using a tracking system to ‘follow the money’, to track the serial numbers of one dollar bills as they made their way around the United States. After a while, patterns developed that indicated the paths that people took (and still take) as their dollar bills changed hands.
The interesting thing about the results is how it can be compared to existing United States population density maps. Knowing how important that population density is to the chances of survival following major disaster, I decided to overlay the ‘follow the money’ map with a population density map, and I added a third layer upon which I drew shaded areas where it appeared that fewer dollars exchanged hands. The assumption that I am made while doing this was that paths or regions that indicate less money changing hands was proportional or related to the travels of humans.
This third layer of ‘fewer dollars traveled’, coupled with actual population density, may provide a more focused view of the geographical regions within the United States that may be more conducive to survival after the apocalypse, should there ever be one.
Here is the map indicating the patterns of human mobility (follow the money). The interconnecting yellow and red lines indicate the paths that money travels. The red lines are more heavily traveled.
I added an overlay in the following map where I shaded areas that appeared to be mostly free of heavily traveled routes. It is all fairly subjective, while some regions are obviously less traveled than others.
In this last map, I’ve added a population density map (including state boundaries) over the shaded map, which now provides a better look as to where the less traveled regions actually are located.
A few observations and thoughts…
The assumption that fewer dollar bills changing hands equates to fewer people traveling the routes is somewhat flawed in that it could also mean that a given region simply has less money to spend, or spends less.
When you look at the shaded region in the south which includes parts of Louisiana, Mississippi, and parts of Arkansas, you can clearly see that the region is fairly populated as indicated by the blotches of red and yellow of the population density map. So, in that part of the country, the fact that there is a bit less money changing hands is probably not so much to do with less travel as it may have to do with people having or spending less money. Having said that, that same region is not nearly as populous as the rest of the east, and may still represent a good choice for a survival location for a number of other reasons…
Hardly any money changes hands near the border of Mexico and Canada. This stands to reason due to national borders and currencies.
Looking at the shaded regions in Nevada makes sense because much of the state is desert. It’s split into two regions because a major freeway runs across it from Sacramento over to Salt Lake City (and all the way across the country).
There’s an interesting swath from southwest Texas up through eastern New Mexico, skirting eastern Colorado and western Kansas.
Then there’s eastern Utah, parts of Wyoming and Idaho, north and eastern Montana, and parts of South Dakota and northern Nebraska.
Oh.. and there’s that bit of upper Maine.
You can see for yourself and make your own estimations by looking at the first map. There are lots of additional factors that go into the formula for an ideal survival location. This observation may simply be one of them. I found it very interesting to overlay the human mobility map (the dollar trail) with a population density map, and to draw observations. Plus, I like maps…