text: The 2004 GaWC (GAWK) rankings identified the Alpha++ (plus plus) type of these things.
full_question: The 2004 GaWC (GAWK) rankings identified the Alpha++ (plus plus) type of these things. Saskia Sassen introduced the "global" type of these things that have a direct influence on the international economy. Ernest Burgess divided these things into circular areas in his concentric zone model. George Kelling developed the broken windows theory after reading a book that claims (*) mixed-use development and density are ways of "generating diversity" in these things. Poorer people tend to be displaced by new development in these locations in gentrification. Walkability is one desired characteristic when planning these areas, whose roads are often laid out in radial or grid fashion. For 10 points, name these densely populated areas whose sprawl has led to the development of suburbs.
first_sentence: The 2004 GaWC (GAWK) rankings identified the Alpha++ (plus plus) type of these things.
raw_answer: city [or cities; or inner city; or urban areas; prompt on "neighborhoods"]