Land Banking is maintaining a sufficient stock of optioned or consented sites to maintain the maximum possible flow of completed units at a realistic rate of return.
Land Hoarding is maintaining a stock of sites over and above the level necessary to maintain the maximum possible flow of completed units at a realistic rate of return, if the land was sold at a market clearing price.
Land Banking is a necessary and acceptable practice. Arguably at the peak of the market as the OFT noted there was not enough of it. Land hoarding is not, it usually represents where a land owner has paid too much for a site and is afraid to write the site off its balance sheets as it is maintained as collateral with banks.
Contrary to Peter Stacey of Turley, householders are in the business of making money from land not so much housing, they are not continental like constriction only firms. They make their money from gaining planning consent, the gift of the community. The problem is simple, housebuilder bought sites at excessive ponzi values before the onset of the great recession. Which is why without any distinction between stock and flow, between genuine and false reasons for holding a stock and without any theory or economic analysis he can claim, despite all of the evidence, including 25% of all sites in London having no intention to develop by the landowner, that there is no problem.
Such taxes have been highly successful in the states, for example for example, Harrisburg, the capital of Pennsylvania, has a land vale tax. Between 1980 and 1995, that tax helped reduce the number of vacant centre structures from 4,200 to fewer than 500, increasing the population by 10%.
 Ronan Lyons, for Smart Taxes Network, Residential Site Value Tax in Ireland, 2011