Nick Szabo grounds monetary value in the unforgeable cost of producing scarcity, and designed bit gold's proof-of-work to manufacture that costliness digitally

In "Bit Gold" (2008), Nick Szabo states the mechanism he takes to underlie the value of precious metals and collectibles: "Precious metals and collectibles have an unforgeable scarcity due to the costliness of their creation." On this account, gold and similar monies hold value not because of an arbitrary social convention but because their scarcity is expensive to fake — nobody can cheaply manufacture more gold, so its supply is a reliable signal of real cost.

Szabo built bit gold to replicate that property digitally rather than argue for it in the abstract: the proposal generates "unforgeably costly bits" via a proof-of-work function, so that digital tokens inherit the same cost-grounded scarcity as a metal, without needing a trusted mint to enforce it. This is the design half of the law: the reason proof-of-work exists in Szabo's scheme (and, downstream, in Bitcoin) is to manufacture the same unforgeable costliness that historically grounded metallic money.

This claim is the anchor half of a broader pattern: value that rests on costly production collapses once a cheaper production method appears — the failure mode Szabo catalogs in claim-szabo-collectible-monies-collapse-when-costliness-becomes-forgeable. Bit gold, and by extension Bitcoin (claim-nakamoto-bitcoin-leaned-on-wei-dai-b-money), was explicitly engineered so that this collapse mode cannot occur — no cheaper "furnace" can ever make a valid proof-of-work forgeable. See observation-unforgeable-costliness-bridges-asteroid-pgm-and-bit-gold for the full bridge.