I spent some time this morning playing around with a nifty tool that breaks down American neighborhood incomes by census tract. It’s a great way to see how divided a city is along income lines. So is DC more income-segregated than other major American cities? Let’s take a look. Green = rich, red = poor, yellow/white = somewhere in the middle. Certainly a striking photo. Wiener then compares our city’s imagery with that of several large cities around the country. As he notes, “DC’s poverty isn’t as concentrated as, say, Philly’s, where there’s just a sea of red in North and West Philadelphia.” Some cities, such as San Francisco, have markedly few lower-income areas; while others, like Houston, TX, lacks single, concentrated areas of one income level. But while those images are interesting, how much can they reveal about a city? For example, does San Francisco have less red than Philadelphia because its residents are doing better economically — or because the city as a whole is unaffordable to those in lower income brackets? We certainly can answer that question, but we would not find the answer in a census tract map. One clear take-away from the DC map: “its sharp dividing line.” Apparently, no line “separates income levels as starkly as 16th Street NW.” The question then arises, how long will that be true? Which lines hold up and which blur and fade away? More importantly, what forces exist (and are needed) to transcend the divisions on the map above?