> You have a naturally occuring resource which is scarce and which nobody created. … Georgist simply say you can use an auction granting you possession for some amount of time …
First problem: This is a recurring process but the land is only "unimproved" at the time of the first auction. At which point no one was interested in the land, there being nothing and noone there, so the auction price is effectively zero. After that first auction you can't say how much of the market price in any later auction is due to the land itself and how much is due to improvements.
Second problem: In order to auction something off you have to own it first, but this is unowned land. No one has the right to sell it—or to prevent anyone else from using it. Land only becomes property after it has been improved. This is also the point where it first acquires economic value.
Third problem: You can't just go auctioning off already-improved land separate from the improvements. The improvements and the land are a single, unified good and in the vast majority of cases cannot be separated without incurring expense akin to rebuilding the improvements from scratch.
Fourth problem: LVT is valued mainly for being a tax on "unearned" external benefits property owners receive from the community, but the "unimproved" value of the property is a poor proxy for net external benefit received by property owners. On the one hand, the value of the improvements also depends on the community; if you build a family home or a restaurant or a warehouse the value of that building is going to depend on the demand for specific kinds of goods in that area and not just the cost to build a similar building. On the other hand, the so-called "unimproved" value of the land is readily influenced by the actions of the property owner, for good or ill. LVT punishes property owners who contribute to the surrounding community by taxing them on any increase in the value of their property which follows from their own contribution to the public good, and rewards property owners who contribute to lowering property values in their own neighborhood.