<blockquote><a href="http://danielkayhertz.com/2014/03/31/middle-class/">Put together by Daniel Hertz</a>, a masters student at the Harris School of Public Policy at the University of Chicago, the maps show each Census tract's median family income as a percentage of the median family income in the metro area.</blockquote>
via <a href="http://www.theatlanticcities.com/jobs-and-economy/2014/04/40-years-chicagos-rising-inequality-one-gif/8786/">40 Years of Chicago's Rising Inequality, in One GIF - Mark Byrnes - The Atlantic Cities</a>.