> (inflation is everywhere and always a monetary phenomenon - the result of too many units of currency chasing too few goods and services, almost always a result of rampant currency debasement, not possible with bitcoin's hard-coded 21 million cap)

Except when it's not, like in Japan which has had a growing money supply but near-zero inflation—and even bouts of deflation—over the last few years/decades:

* https://fred.stlouisfed.org/graph/?g=PA7P

And in other places as well:

> In this paper I will argue why the common misconception that “inflation is always and everywhere a monetary phenomenon” cannot be used to explain most historical hyperinflations. I will argue that “money printing” is often the response to exogenous and unusual events and not the direct cause of the hyperinflation.

* https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1799102

> Currently, it appears impossible to forge or fake Proof of Work, the way governments can forge and fake new currency into existence with a few keystrokes, which again, is the ultimate cause of inflation.

Except it's not governments, or even central banks, that create money, it is banks through credit creation:

* https://www.bankofengland.co.uk/quarterly-bulletin/2014/q1/m...

Further, all of this talking about inflation like it's a bad thing.

I think most people recognize that deflation, and the economic causes of it, are a bad thing, e.g.:

* https://en.wikipedia.org/wiki/Great_Depression

As we've (re-)learned recently, "high" inflation (say >4%?) is also not great. So we're in the range of 0-4% to consider. It may be thought that 0% inflation is ideal, but that is impossible to achieve. You'd think that having a fixed currency supply would do this (e.g., gold standard) but this actually moves deflation as the 1930s showed:

> The initial contractions in the United States and France were largely self-inflicted wounds; no binding external constraint forced the United States to deflate in 1929, and it would certainly have been possible for the French government to grant the Bank of France the power to conduct expansionary open market operations. However, Temin (1989) argues that, once these destabilizing policy measures had been taken, little could be done to avert deflation and depression, given the commitment of central banks to maintenance of the gold standard. Once the deflationary process had begun, central banks engaged in competitive deflation and a scramble for gold, hoping by raising cover ratios to protect their currencies against speculative attack. Attempts by any individ- ual central bank to reflate were met by immediate gold outflows, which forced the central bank to raise its discount rate and deflate once again. According to Temin, even the United States, with its large gold reserves, faced this con- straint. Thus Temin disagrees with the suggestion of Friedman and Schwartz (1963) that the Federal Reserve's failure to protect the U.S. money supply was due to misunderstanding of the problem or a lack of leadership; instead, he claims, given the commitment to the gold standard (and, presumably, the absence of effective central bank cooperation), the Fed had little choice but to let the banks fail and the money supply fall.

* http://www.nber.org/chapters/c11482

And if you think having a hard currency helps with stability, the historical record of the hold standard shows that is not the case:

* https://archive.is/https://www.theatlantic.com/business/arch...

So if <0% doesn't work, and >4% does not work, and 0% does not work, we're left in the situation of going for an interval of (0,4).

Further a fixed currency supply ties the hands of policy which leads to stability. You want to be able to create money when economies slowdown and private aggregate demand drops:

> I would summarize the Keynesian view in terms of four points:

> 1. Economies sometimes produce much less than they could, and employ many fewer workers than they should, because there just isn’t enough spending. Such episodes can happen for a variety of reasons; the question is how to respond.

> 2. There are normally forces that tend to push the economy back toward full employment. But they work slowly; a hands-off policy toward depressed economies means accepting a long, unnecessary period of pain.

> 3. It is often possible to drastically shorten this period of pain and greatly reduce the human and financial losses by “printing money”, using the central bank’s power of currency creation to push interest rates down.

> 4. Sometimes, however, monetary policy loses its effectiveness, especially when rates are close to zero. In that case temporary deficit spending can provide a useful boost. And conversely, fiscal austerity in a depressed economy imposes large economic losses.

* https://archive.nytimes.com/krugman.blogs.nytimes.com/2015/0...

After the 2008 GFC it took many years for unemployment rate to go down in the US because there was no fiscal stimulus (due to GOP hampering it). Post-COVID, with giant stimulus the unemployment rate is the lowest its been in decades: that's what monetary flexibility gives you: options to help get the economy going again.