Ok fine. My strong reaction was really due to the use of the word "simulator". But if you say model - yeah, central banks do that. I'm not really familiar how

Ok fine. My strong reaction was really due to the use of the word "simulator". But if you say model - yeah, central banks do that. I'm not really familiar how public their models are. I would bet you that they intentionally don't want people to know "here's the exact model and here's the exact inputs", because they want to keep some discretion for themselves. They want to be able say "I know that this model with these inputs says X, but as a thinking human being I know that the model doesn't account for Y which has been crucial in these past few months, and so instead of X we'll do Z". What you said makes a lot of sense, but it would require collaboration from the decision makers. There's no incentive, I believe, for someone to do this "open source stye", because the moment that their effort pays off, some hedge fund will take it and use it to trade on it.