If the problem with Detroit's declining population is people moving to the burbs, then why can't the City of Detroit start annexing neighbouring cities to regain its population and tax base? Detroit has only 138 square miles of land, while Chicago has 228 square miles, Toronto has 243 square miles and New York City has 305 square miles.
In 1996, the Provincial Government amalgamated the City of Toronto with the surrounding municipalities of East York, Etobicoke, North York, Scarborough and York to create a new City of Toronto. Streamlining also saved $138 million a year.
Why can't the same thing be done with the City of Detroit?