Me and pimp are refering to this: "If you brought a group of economists from 2008 to the present day and told them that central banks had bought $9 trillion in assets and were still looking for ways to boost inflation, I don't think they would believe you," said Michael Pearce, global economist at Capital Economics.
Despite the massive amount of money pumped into the markets inflation barely showed, certainly less inflation showed then what economists expected or then what models predicted. And those 9 trillion are on top of low interest rates as they came through QE.
The current proposal in the US would put an additional 3.84 trillions onto the markets ( thats approximate), this sum could most probably be reduced by around 1 bio as i m pretty sure some benefits that are paid by the government would be cancelled.
Now if you consider that for around 20-25% of the population an increase of 1000$ per month wont change their spending and most of it will just lay on some bank account or go into fin markets most probably.
So again if we d really see real inflation that cannot be combated or that would erode the benefits of the UBI is very questionable.