Yes, when you read that St. Louis, say, "lost" 600,000 people over the last 60 years, everybody should understand why that's a ridiculous fiction. Those people

Yes, when you read that St. Louis, say, "lost" 600,000 people over the last 60 years, everybody should understand why that's a ridiculous fiction. Those people didn't leave St. Louis. They moved slightly west across invisible and arbitrary 150-year-old political borders that have no relation to the built environment of the region today. They still live in "St. Louis" by any commonsense definition. It's the same all over the Rust Belt. So what really happened? We built new subdivisions for the exact same set of people and the old parts of town just fell apart entirely. The maintenance was completely ignored. Nobody left St. Louis. They just took developer and federal money and built new housing in St. Louis County (the original suburbs). And then when those old suburbs started to decay, they did it again by moving out to St. Charles (the new exurbs). The latest wave of this is the "return to the city" movement in which the same set of people continue the cycle by abandoning the housing that was built to replace the housing they're returning to. I'm using St. Louis as an example here, because it's the city I know the most about, but it's the same everywhere.