The problem I am most aware of is land banking by developers on the edges of settlements. This and other forms of land speculation drive up the value of land out of the reach of ordinary people. Speculators, the rich, and so on are the only people to benefit from this. People are being priced out of London, it's a mad situation. This policy does not support affordable housing nor people who would like to buy land to build their own homes or grow food locally. A tax Is not the answer because it further puts up the price of land. I agree that a top-down (at local level) solution is required that gives tax breaks or reduced rates to more sustainable uses of land. A carrot, not a stick.