Someone was building a similar one where AI agents run economies. I feel like it's a great way to quickly prototype different economic models and their effects.

Eventually we could have live demos of policy interventions the same day as they're announced

While this might be fun, it definitely wouldn't be plausible for economic modeling. LLMs aren't companies and people, they won't behave as a real economy does, or even any decent approximation, even if you could orchestrate a few million agents. For example, a real human, if you were to ask them a complex question that requires deep web searches, data corroboration, etc would ask for recompense before doing any of the work, while an LLM will just do it. I think this alone suggests how well they would model real economic agents.

Do you have a link to this? Sounds very interesting.

Another idea I had was simulating an entire town with an LLM representing each person, which sounds somewhat similar.