The problem at the root of shrinking cities is a lack of funds to consolidate space. The downfall of one property is the anchor that pulls down the value of adjacent properties, and so on until you get the picture below.

Notice however that the photo also contains a pristine new road running alongside the blighted space.
This could be the missing ingredient to getting a shrinking city to stabilize about a right-sized city.
A network of low-cost transportation and linear parks would soak up the depopulated space and remobilize the people around a new engine of economic growth built on choice, access, mobility, and space.
The funds for revitalization come from transportation taxes distributed fairly on a per capita basis. This is the seed money that gets the process rolling in the right direction.
The public then decides on the spaces that need to be maintained and enhanced, and the open spaces that need to be consolidated and converted to parks, urban farms, walkways, bikeways, and share-ways (medium volume through roads that take light-duty rideshare vehicles).
Revitalizing existing cities takes the pressure off of magnet cities while making low-cost housing available in heritage areas.
For more on our eco future download Green at No Cost.
For more on Shrinking Cities go to https://nextcity.org/daily/entry/shrinking-cities-us-urban-planning.