The Tamil Nadu state government (and a few other states), in India, did something like that - when the real estate market fell a bit, the government noticed tha

The Tamil Nadu state government (and a few other states), in India, did something like that - when the real estate market fell a bit, the government noticed that the developers were still holding on to many ready-to-occupy flats (condos) in the hopes of getting a higher price later. The government immediately issued a notice that once a residence is constructed by such developers and is ready-to-occupy, property tax and utility bills (for water) has to be paid for it whether it is occupied or not. Thus builders stopped building in excess or holding on to it to cut supply and artifically raise demand (and thus prices).