The Bank of England have published an interesting note on money creation. Given that Kaleidic publishes our own measure of the UK money supply, there is plenty that could be written about it. For now though, I just want to nip some of the crowing being done by MMTers. The way I understand the "money multiplier" is that there's a ratio between narrow and broad money. It's a bit like saying that there's a link between changes in human generated CO2 emissions and in average global temperatures. But identification of a ratio says nothing about causality. In the case of global warming, it seems that there is a large and vocal group claiming that the ratio (or correlation) is stable, predictable, and underpinned causaility. There's others who dispute this. There's probably even some who argue the causation runs the other way.
In the BoE report they say:
Another common misconception is that the central bank determines the quantity of loans and deposits in the economy by controlling the quantity of central bank money — the so-called ‘money multiplier’ approach.central banks implement monetary policy by choosing a quantity of reserves. And, because there is assumed to be a constant ratio of broad money to base money, these reserves are then ‘multiplied up’ to a much greater change in bank loans and deposits
While the money multiplier theory can be a useful way of introducing money and banking in economic textbooks, it is not an accurate description of how money is created in reality. Rather than controlling the quantity of reserves, central banks today typically implement monetary policy by setting the price of reserves — that is, interest rates