[mattgibson]

Land prices go up when poeple have more mooney and go down when people have less. The root cause is that land is unique in the economy because it both cannot be manufactured and cannot be moved. Each piece of land is therefore unique and no one can increase supply in response to demand. Renting or purchasing land is essentially an auction and the price is set by the highest bidder. Economists call this a "monopoly price" because it's the same effect you would get if someone has a monopoly and can raise prices at will. This is in contrast to competitive prices which sink lower and lower until they bump up against the actual cost of getting the work done to provide that product or service.

Land value is therefore a really weird part of the economy that allows people to charge money without doing any work or providing any value in return. If we confiscate all the money people charge to rent or buy land, nothing changes because no work was ever happening. The land is still there and still just as useful. Contrast that with anything where work is actually done - the industry would collapse if you confiscate the money. Taxing land value therefore allows the government to reclaim the money which those people should not be able to charge in the first place (if there was free market competition). When this happens, counter-intuitively, land prices do not rise (because the highest bid in the auction doesn't change) and there is no negative affect on production or jobs (because no one is employed to manufacture or maintain land). We know this because economic theory predicts it and various countries have already tried it. Instead, other taxes can be cut or eliminated due to the enourmous boost in government income, which has very positive effects on the rest of the economy. Understanding how this works is deeply counter-intuitive and so people usually think that a shortage of buildings is driving property/land values because it's easy to make sense of.

To directly answer your question: if you tax the land value as set by the current market, you don't have to worry about assessing other factors that SHOULD lead to higher taxes because the people trying to buy the land have already done that. That's why they are offering a higher price. It's simple and therefore cheap and easy to administer. Also essentially immune to tax dodging because you can't hide the asset.

[nonethewiser]

> Land value is therefore a really weird part of the economy that allows people to charge money without doing any work or providing any value in return. If we confiscate all the money people charge to rent or buy land, nothing changes because no work was ever happening. The land is still there and still just as useful. Contrast that with anything where work is actually done - the industry would collapse if you confiscate the money. Taxing land value therefore allows the government to reclaim the money which those people should not be able to charge in the first place

You say they shouldn’t be able to charge for it, but instead of disallowing it you just change the beneficiary?

[mattgibson]

Given it's an auction mechanism, it's hard to stop people offering to pay for the land they want. The options seem to be either allowing that money to flow into private hands so someone gets a free lunch, or to capture it as tax, enabling all other taxes to be reduced or eliminated. The latter seems fairer to me as it eliminates the free lunch and keeps people's earnings in their own pockets via e.g. eliminating income tax.