> This isn't a unique problem, and we need a plan for healthy shrinking of cities and countries.
I'll add as someone from the rust belt, while we do need to understand how to shrink cities, a lot of this shrinking in the central city was self-inflicted by sprawl.
The metro populations of many of these rust belt cities stalled out in the 1950's-70's but for the most part has been relatively stable since then. Yes, wealthy industry closed or left, but the population was still there.
However short-sighted suburban sprawl, poor planning, and racial segregation hollowed out the central cities while urbanized area doubled or quadrupled the infrastructure a region needed to support. Suburbs boomed with new infrastructure while the city was cannibalized.
Urban sprawl in Cleveland - same metro pop in 1948 as in 2002, at least 3 times the land area
http://www.urbanophile.com/2018/03/16/sprawl-in-its-purest-f...
Same story with urban sprawl in Buffalo - same metro population, triple the urbanized area
http://www.urbanophile.com/2010/04/27/chuck-banas-this-is-sp...
Unfortunately there seems to be no political will to stop, even as it consumes the older suburbs now. Subdivisions, new roads, sewers and office parks continue to be thrown up on the edges while a new wave crumbles. The low density of the sprawl can't generate enough revenue to sustain itself - but by the time the bill comes for renewal, the developers have already moved on to a new ring of exurbs.
I wish these cities would look towards regional planning and government like Portland and Toronto.
https://en.wikipedia.org/wiki/Greenbelt_(Golden_Horseshoe)
https://en.wikipedia.org/wiki/Urban_growth_boundary