With land, the issue is the same. Even though improvements aren't factored in to the value the same way they are with property tax, what makes one parcel land more valuable than the other? Such a value isn't determined by a linear relationship. So where would one get the number from?
Here is the last conversation I had about the topic. https://news.ycombinator.com/item?id=27032163
- look at comparable empty lots that are sold. Even in big cities there are empty lots sold.
- look at the purchase price of buildings + land and subtract out the construction cost of the building
You can also combine the above, e.g. look at two similar buildings with similar construction costs built in two different places to infer the relative price of land in each.
You can get a pretty good estimate from the above techniques. OFHEO supplies such estimates.
> what makes someone's land more valuable than the other?
Like any other good, people bid on it and so a price is set. Having land allows you to build a building or store so things like zoning laws, demographics, income of people, foot traffic, nearby amenities, these all contribute to the value of land. Land in sunny Miami Beach is worth more than land sitting atop a superfund site somewhere in frozen Michigan. Downtown land in San Francisco is worth more than farm land in Iowa. The reason for this is you can make more money with land in one place than another, even if you need to invest in structure to make that income stream a reality.
To your second point: You understand that land has differing value/utility to each purchaser or potential purchaser. LVT does not recognize this. It only assumes that if you have more land, you should be taxed more. The farmer would obviously suffer in comparison to the city dweller.
However, as a critique of your point, few San Franciscans make actual money off their land or real estate (landlords excluded). The fact that they *can* make money off their land, does not mean they are. To be taxed as though one were making money off of land is to use a legal fiction to justify a particular policy. It doesn't solve an inefficiency in land distribution but creates one.
Did you really have to take away all that with a pithy explanation of reality? Why not just let him have his day in the sun?