There are many ways to contextualize America's growing economic and racial inequality: through the growth of new tech hubs in old industrial cities, the cost burden of inadequate transit access, or simply by comparing the lowest and highest earners in each region.
In the case of Chicago, this series of maps, which show the disappearing middle class since 1970, may be the most striking and easy-to-process yet:
Put together by Daniel Hertz, 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.
As Hertz says on his blog, it's easy to see these maps as a "direct consequence of rising income inequality." But researchers Sean Reardon and Kendra Bischoff, who inspired Hertz, say there's more to it than that. They determined in a 2010 study that not only is there "a robust relationship between income inequality and income segregation" in the country's largest 100 MSAs, but that it's had larger effects on black families than white ones.
Racial and economic inequality is nothing new for Chicago, but observing the unfortunate trend as Hertz points out, reminds us that "a happier alternate reality" existed not that long ago.