Na verdade, já houve uma entrada mais lá em baixo acerca do tema (Dinheiro de helicóptero), mas acho que esta acrescenta mais um pouco. Helicopter money and the government of central bank nightmares (Simon Wren-Lewis).
Here it is perhaps easiest to talk about monetary policy as putting money into the system when inflation is too low or taking it out when inflation is too high. QE creates money when interest rates are at their Zero Lower Bound (ZLB), but that money can be taken out of the system later if need be by selling the assets that QE buys. Helicopter money also puts money into the system at the ZLB, in a much more effective way than QE, but it cannot be put into reverse by central banks alone. The central bank cannot demand we pay helicopter money back.
If the government cooperates, this is no problem. The government just ‘recapitalises’ the central bank, by either raising taxes or selling more of its own debt. Economists call this ‘fiscal backing’ for the central bank. In either case, the government is taking money out of the system on the central bank’s behalf. So the nightmare that makes helicopter money taboo is that the government refuses to do this.
What kind of government would this be? Inflation is rising, and the institution tasked with bringing it back under control makes a request that can be satisfied fairly painlessly by the government issuing some more debt. A government that refuses to do this is saying very publicly that it no longer cares about high inflation: it prefers an environment of low interest rates and high inflation and it is prepared to cripple its central bank to achieve this.
Now imagine a government with these preferences, and now put it in a world where the ICB does not need recapitalising and is selling assets and raising interest rates to do its job. Are we really meant to believe that such a government would ignore its preferences and let the central bank get on with it? Of course it would not – it would take away the central bank’s independence by forcing it to stop raising interest rates.
In other words, a government that would refuse to recapitalise an ICB is also a government that would have no hesitation in ending central bank independence. Holding assets is no protection for an ICB against this government of its nightmares. 
The reason we have independent central banks is not to stop us becoming like Zimbabwe. It is to stop governments taking small risks with inflation for short term political gain. Like the occasion I was told that the Chancellor (at the time) knew full well that interest rates needed to rise now to reduce inflation, but there was no way that would happen until after the party conference. But this kind of government is not the kind that would deliberately sabotage its own central bank by refusing a request for recapitalisation.