Specifically, the Washington, D.C. City Council, which has voted to double the property tax on vacant properties, to $10/$100 evaluation (that’s right 10%, it had been 5%, as compared to $1.85/$100 for commercial properties, and $0.85/$100 for residential properties).
Additionally, the Council has made it more difficult to get an exemption, cutting back on the numbers of exemptions granted, though there is still a 3 month exemption for a property for lease, a 1 year exemption for residential property for sale, and a 2 year exemption for commercial property for sale.
In many inner cities, vacant properties blight the landscape, and this is a very good way of dealing with it.