Yes, fried chicken is stereotypically a southern-US (poor part of the country, for a variety of historical reasons) and even more stereotypically African-Americ

Yes, fried chicken is stereotypically a southern-US (poor part of the country, for a variety of historical reasons) and even more stereotypically African-American (poor segment of the population, similarly due to all sorts of historical issues from slavery to overt discrimination to more recent covert discrimination). Which means that fast-food restaurants specializing in fried chicken are a pretty strong economic marker. On the flip side, coffeeshops have a connotation of being more a middle-class thing. So tracking coffeeshops vs. fried chicken would be a very obvious way to map affluence in the US.