> For the complete documentation index, see [llms.txt](https://docs.moduluszk.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.moduluszk.io/economics-fees-and-state/what-is-priced-instead.md).

# What is priced instead

In a proof-carrying chain, computation cost falls on whoever produces the proof, which is the submitting party, so computation is self-priced and a deliberately expensive predicate harms only its author. The network's scarce resources are therefore bytes and persistent state, and the fee model prices exactly those: transaction size, and state occupancy \[A]. The live precedent for pricing occupancy is Ergo's storage rent on long-unspent state, which Ergo's own documentation frames as making state growth controllable and predictable \[S].