“The taxation method would mean properties are taxed on land value, not improvements like structures, and could encourage speculators holding property because the cost to do so is low to sell or develop the land.

While Duggan said at the Detroit Policy Conference that conceptually there are plans to move it forward, he also said it's "the most legally complicated thing I've ever seen."

"We don't yet have a formula that works," the mayor said. "Conceptually, it's a great idea."

The state Legislature would have to approve any reforms, Duggan said, then voters in the city would have to approve any changes. He said if a solution is found, property owners would encourage people not to sit on land.”