Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Redrawing our borders

19.11.2010
Researchers follow the money to show complicated ways people connect

What are borders these days? When travel was local, borders and communities were easy to define, but now our connectivity is more complex. It's time to think of borders differently, according to Northwestern University researchers.

To reflect today's reality, they have taken a look at human mobility and redrawn the borders within the United States, showing areas of the country that are most connected. Some of the borders in this new map are familiar, but many are not.

The research team, led by professor Dirk Brockmann, used the wealth of data generated by Wheres's George? (wheresgeorge.com), a popular website that tracks one dollar bills spent across the country. The many millions of bank notes, having been passed from one person to another, represent links between geographic places.

An award-winning video produced by Christian Thiemann and Daniel Grady, doctoral students and members of Brockmann's research group, illustrates the work: http://www.northwestern.edu/newscenter/stories/2010/02/money.html.

Some divisions were expected, but many were a surprise. Some of the most significant borders split states, such as Illinois, Wisconsin and Pennsylvania. This initially puzzled the researchers, but people who have seen the research and live in those areas say the borders reflect cultural segmentation and the pull of certain large cities.

"We also thought that the strong, long-range relationships, such as between Los Angeles and New York, would overshadow the local, short-distance travel, but it did not," said Brockmann, associate professor of engineering sciences and applied mathematics at the McCormick School of Engineering and Applied Science. "The short distance travel has a stronger impact."

Some community divisions fall along more familiar lines, such as purely political boundaries (state lines), political boundaries that reflect geography (the Mississippi River) and others caused entirely by a geographical feature (the Appalachian Mountains cutting through West Virginia).

The study will be published Nov. 18 in the journal PLoS ONE.

The work already has attracted the attention of diverse individuals and groups wanting to know more about the "mobility neighborhoods." The Federal Reserve System is interested. Commuters to Chicago from northwest Indiana are interested. And a leading American linguist is interested.

"The well-defined geographic areas we found show us how people really interact and are connected," said Brockmann, who also studies how infectious disease spreads. "These results open up pathways for investigation in a variety of areas."

Where's George allows anyone to record a bill's serial number and then track its journeys as other people spend it across the country. Every time a dollar is spent in a new place, it means someone moved it there. Research has shown that this flux of money data is a good proxy for human mobility. The very large database is truly multiscale: links span thousands of miles, hundreds of miles and just a few miles.

"Think of these links as an attractive force connecting two places," said Brockmann, a member of the Northwestern Institute on Complex Systems. "The social and mobility ties represent a gravitational pull of sorts."

The information could be valuable to the Federal Reserve for optimizing the transportation of money among the 12 regional Reserve Banks across the United States. A professor of linguistics from the University of Pennsylvania wants to use the travel boundaries in his studies of regional dialect boundaries. The findings support those in northwest Indiana counties who feel more connected to Chicago and favor being in the same time zone. And anyone involved with planning large-scale infrastructure, such as high-speed rail, who needs to know where people want to go, can benefit from the human mobility map, Brockmann said.

Using supercomputers, Brockmann and his team applied a random algorithm to the Where's George? data, which collects counties into groups. The traffic within each group is very high -- very connected -- compared to the traffic between the groups. They ran the algorithm thousands of times, with each run producing a slightly different map. Then they took the results, overlaid all the maps and produced one single map, showing the strongest boundaries.

The video, "Follow the Money: Human Mobility and Effective Communities," won first place in the 2009 International Science and Engineering Visualization Challenge, sponsored by the National Science Foundation and the journal Science.

The title of the PLoS ONE paper is "The Structure of Borders in a Small World." In addition to Brockmann, Thiemann and Grady, other authors of the paper are Fabian Theis and Rafael Brune.

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Studies and Analyses:

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>