Not sure what the issue is. Friedman did come up with the helicopter jibe to say that public spending was, in his words, always and everywhere inflationary. Yes he used it against Keynes, but also against FDR and the Deal. What are you saying is incorrect?
I suspect we might be talking at cross purposes, so rather than go over the previous quotes I shall just say what I think as plainly as I can. Some of this therefore might be slightly repetitious.
Keynes rewrote the understanding of how money and interest rates work in the General Theory. In part he wrote about how we could use monetary financing to fix problems in the economy under specific circumstances. Specifically when interest rates are low and there is a net excess of savings (i.e. a liquidity trap) and this is what he said in the famous quote about paying people to dig up money I quoted above. Note also that even Keynes in the 1930s said it was better to spend it on infrastructure rather than just giving it out.
Friedman then attempted to ridicule this notion with the helicopter money jibe. Although he did this in the context of a paper where he was arguing that we could control both aggregate demand and inflation by controlling the money supply (i.e. Monetarism) a theory which would then be tried to disastrous effect by the Thatcher government.
Helicopter money has since become a way to talk about this type of unconventional monetary policy. Mostly this is a colloquial usage, although Bernanke famously used it in connection with policy back in 2003, the point being that it is used as a shorthand and not as a reference to Friedman's critique. In most cases I have come across in the last 20 years people mean it in this sense rather than as a Friedmanesque argument what Keynes's meant about the limits of monetary policy.
BTW Freidman didn't argue that public spending was always inflationary but rather that *monetary expansion* was always inflationary when it is in excess of the rate of growth of the output of the economy. At least that has always been my understanding. Although it quickly gets more complicated when one starts to think of sectoral balances, crowding out, expected inflation, etc. which is all mostly beyond my knowledge to argue about in any detail.
In modern times, of course, we wouldn't bother with the paying people to dig up money bit and would just give them money preferably in some way that maximised the chances of causing economic activity and minimised the chances of causing inflation. For example, paying people's gas bills directly instead of giving them money.
Well, we could pick through that, but still not sure how any of that contradicts anything I’ve said. Take a look at 3), yes Keynes contradicts or at least questions Classical quantity Theory of money, so does MMT. Monetarism adopts it.
My argument there is those points come directly from Keynes in 1937 and we don't need MMT to make those arguments. We get our understanding of modern money from Keynes, the subsequent abandonment of commodity money and the increasing number of examples where it seems the scope of Keynesian economics is broader than we thought.
So the two things I never understand about MMT are:
1) What is it suggesting that is not in Keynes? I mean in practical terms as I thoroughly believe that within the conventional Keynesian thought we have enough scope to address recessions, the green new deal and so on and all that stops us are essentially political choices about where we choose to spend and distribute money. I do not see how the scope of seigniorage from MMT offers much extra scope, especially in the context of a real world experiments where we just spent literally $trillions on QE.
2) How does MMT prevent inflationary spending? Keynesian economics has a bunch of stuff to say about aggregate demand, output gaps, etc. etc. and I never see any of that in MMT other than vague talk of independent spending boards. I would be deeply concerned about the chances of future governments abusing this.
Ultimately we might well say that how government funding and taxes work is all essentially an elaborate polite fiction but I don't believe (or have yet to be convinced) that this fiction prevents us from doing anything which we could currently do if we had the political will and economic capacity. I also think, at least to some extent, this fiction acts as a constraint about what is possible and if you remove that it would get out of hand quite quickly.
So explain to me not the semantics of what money means or how it works, but what, specifically, is in MMT that is not in Keynes and exactly how much more and why this allows the government to spend and under what circumstances.
OK, but still not sure if you are working from Monetarist assumptions or Keynesian ones
I have never been any sort of monetarist and my politics and economics are firmly from a Keynesian point of view.
The only caveat here is that the definition of Moneterism seems to have changed over my lifetime and now means more than just Friedman / Thatcher / Reagan claims that you can control aggregate demand and inflation by controlling the rate of growth of the money supply.