That's a tricky problem to solve. I work with the NYC government on some projects, and they actually do seem to keep pretty decent track of all of the city's p

That's a tricky problem to solve. I work with the NYC government on some projects, and they actually do seem to keep pretty decent track of all of the city's properties (at least, my experience with this is with the tax and finance people who assess every property in the city annually). Empty space is generally not fungible. A vacant upstairs floor of a police department couldn't be turned into elementary school classrooms, for example. But the NYC government owns a lot of properties, and rents space from private owners, and there are definitely inefficiencies that could be eliminated. Tracking all of this would be a fun project to work on.