[nonethewiser]

What’s currently stopping people from developing them though? Detroit is a huge city and its population has largely vacated to the suburbs. Maybe they havent been developed because the current demand is already being met.

[mactrey]

Sure, that's possible. Or maybe Mr. Parking Lot Owner just likes the look of parking lots. But the key point is that today, improving the land is disincentivized because it would increase the owner's tax burden. So we don't know exactly what people would do with all those empty lots if improving them wasn't disincentivized.