It also means (and by "means" I mean "necessitates" or "requires") decay. Suburban development in metros that aren't otherwise growing guarantees decline elsewh

It also means (and by "means" I mean "necessitates" or "requires") decay. Suburban development in metros that aren't otherwise growing guarantees decline elsewhere in the region. Sometimes people look at a place like North St. Louis in disbelief -- "how could all these houses have been abandoned?" -- without ever considering the fundamentals. The region has expanded to cover hundreds of square miles of new development since 1970 all with like 1% population growth. They doubled the number of houses, but they didn't double the number of households. Decline is an illustration of the pigeonhole principle. So it's not just that the new suburbs are too low-density to support themselves; they also create the conditions whereby the old parts of the city also de-densify to unsustainable levels.