> The unimproved value of the land (I.e. the basis of taxation in a Georgist scheme) is definitionally exclusive of things that happen on the land.
Ah yes, "let's define away the problem."
> Of course some portion of the taxes go to Disney. Who do you think pays for the air travel system that brings people to Orlando or LA? Who pays for the freeway system that brings in the food?
The typical argument is that Disney doesn't pay enough for those things. No one thinks that such things are "money going to Disney", which just goes to show the absurdities that you have to accept when trying to paper-over the problems with Georgism.
> I am very curious to hear your examples of improvements/activities on land that become part of the unimproved value of land at a fast enough rate to matter?
Who said that "improvements/activities" are the only way for the unimproved value to change rapidly? The land around Disneyland is a counter-example.
As to your suggestion that there aren't examples that fit your absurd restriction, I'll point you to the super-fund sites where SV fabs used to be.
As I hinted earlier, having a cute equation is no substitute for critical thinking.
> Obviously the unimproved land has a market price $X and then the land + structures on it have a different price $Y.
The question is not whether they have prices, it's whether they can be determined.
It's reasonably easy to determine the market price for their sum. How, exactly, do you separate them?
BTW, you're probably assuming that improvements necessarily have non-negative value. That's actually wrong.