An appropriate land value tax is proportionate to what improvements the community expects to be present on the land on average -- that is, how desirable the are

An appropriate land value tax is proportionate to what improvements the community expects to be present on the land on average -- that is, how desirable the area is as a whole. That should scale pretty well on a school district level. As for discouraging speculation, property and land tax schemes can both be used. However, in an environment in which other landowners are improving, the tax burden of a speculator just sitting on their property goes up under a land value tax.