In dream-world, we'd never have problems like this! A constructive alternative to Detroit's problem? They should have declared bankruptcy a long time ago, before levering up their debt with bond schemes.
I'm not sure it counts as a constructive alternative if it requires time travel.
I do. Raise property taxes and sales taxes until you can pay your bills. The solution is actually simple. It is impossible for elected officials to do and keep their job, but simple.
That might not actually work, seeing as how Detroit already has a population problem and higher taxes will probably force even more of them out, leading to flat or lower overall revenue.