What are the assumptions of the model? Who would make the model? Who would trust the model? How long until the unchanging underlying assumptions blow up under

What are the assumptions of the model? Who would make the model? Who would trust the model? How long until the unchanging underlying assumptions blow up under the added pressure of fiscal policy for the most important currency in the world leaning on them? Inflation is one of the most important metrics for healthy governance, right up there with 'what wars are we fighting?' You really don't want it to be any more game-able than it has to be.