The interactive map Where Does the Money Go? [stamen.com] by Stamen Design reveals the financial impact of the movements by the U.S. during 2009, on a county-to-county level. More specifically, Stamen used an open dataset containing all changes of residential address as reported to the IRS to figure out where people were moving to (blue lines), and where they originally came from (red lines).
In addition to a short description of insights (like how the migration across the country is oddly parallel to the movement of money), Stamen released an extensive documentation of their iterative design process behind this minimalistic-styled map.
This project is part of a recent challenge from Esquire magazine to 5 designers, architects, and artists, to rethink the concept of the map while depicting what is happening in the country today.