This could be an example of Simpson's paradox[1]. You can't determine where people are moving based on which map has the most black lines. [1] http://en.wikip

This could be an example of Simpson's paradox[1]. You can't determine where people are moving based on which map has the most black lines. [1] http://en.wikipedia.org/wiki/Simpsons_paradox http://en.wikipedia.org/wiki/Simpsons_paradox