How do you define and evaluate unimproved value?

I'm assuming by that they mean the value of the land.

And if it's done similar to an appraisal they see what market price is for a sale (which combines the value of the building + land). Then they can estimate how much it would cost to rebuild that building if it were completely destroyed. That's the value of the improvements. The remainder is the amount someone implicitly paid for the land.

This is not great because suppose it cost relatively little to physically build a house but you sold it for a huge amount because it's in some chic architectural style that hasn't arrived yet in this city. So your house was in a crazy seller market and unexpectedly sold for crazy tons. Now you are being seriously penalized for your boldness.

And what are we talking about 0.0001% of all homes ever built? Even less?

Someone can always come up with a contrived example to find a short coming in a rule or law. That doesn't make the law not sound or wise.

"Speeding shouldn't be illegal. What if there is a tornado behind you and you need to rush to get away from it, but you go faster than the speed limit to save your life? See, we can't have laws for speeding."

No, because the tax is only on the price someone would pay for the lot.

Restating the definition does not magically conjure a sensible strategy for arriving at that value.

So far, our comments have boiled down to "Yes you can assess unimproved value of improved land", and "No, you can't, there is no way to get that number separate from the value of improvements."

So I'm going to try to say something different.

1. Here is the article that convinces me it is very possible to assess land separate from improvements. It details several strategies for doing so. Also properties are assessed in these ways already in many places. https://astralcodexten.substack.com/p/does-georgism-work-par...

2. Accuracy of assessment does not need to be super high for this idea to work. You just need an assessment with the intent of assessing unimproved land. The tax does not need to be literally 100% of unimproved land value, it just has to be a high percentage. Let's say there is a +/- 30% accuracy of unimproved land value assessment. We can have a 70% tax on that assessed value. Some people would in actuality be taxed at 97.5% of land value, and some people at 52.5% of land value. Perhaps the unfairness of this discrepancy is a true downside. However, one could argue the same about property taxes now.

You can’t and that’s why such a program is popular with politicians.

The bigger issue is with vacant properties being used as cash stores.

> You can't

Sure you can. Unimproved value of the land is simply the value of the lot as a whole minus the value of building that sits atop (well, improvements aren't always buildings, but that's a simple example). You can approximate it by comparing it against the transaction prices of nearby lots that aren't improved, or by taking the construction cost out of the purchase price of the lot.

> is popular with politicians

Land value tax in general isn't that popular around the world, and Henry George's version of it, where all tax is replaced with just a land value tax, even less so. As far as I'm aware, there is literally no jurisdiction in the world whose sole tax revenue is from LVT. Economists and idealists like land value tax; politicians, who derive a lot of power from the wealthy landowning class (who in turn would be the most hurt by LVT), not so much.

> The bigger issue is with vacant properties being used as cash stores.

Land value tax would be an excellent way to curb real estate speculation.

So a unit that abuts the el should have the same per acre value as a unit a block and a half away?

Clearly you need comps to figure it out. It is certainly possible especially in the data driven world we have today.

How did that work out for Zillow?

What would the unit cost if it were an empty lot? That is the tax.

Until you get the capability of temporarily creating a parallel universe and rolling it back, It's an unanswerable question, that's the point. Also you are confusing cost for price.

Denmark must be capable of creating parallel universes then.

https://en.wikipedia.org/wiki/Taxation_in_Denmark#Land_value...

That’s no more true under LVT than it is today.