[dionidium]

Size isn't the salient factor. Consider two "cities," one of which draws its political borders around its inner suburbs and one that doesn't. They may have identical populations, even, but they'll produce very different results on many common statistical measures.

This is why you should almost never compare two places based on political borders or designations. (You have to instead normalize around something less arbitrary. "City" and "state" aren't proper categories for classification, because what gets included from city to city and state to state can vary across multiple dimensions.)