They set monetary policy based on their forecasts of the economy. In principle, they could set their monetary policy target at whatever level they choose, but i

They set monetary policy based on their forecasts of the economy. In principle, they could set their monetary policy target at whatever level they choose, but in practice they're just responding to the economy, so they have a great deal of uncertainty about their own decisions.[1] [1] There's also the matter of changes in the voting members of the FOMC over time.