Thanks for that post - now that's something to work with!
The Gross World Product (GWP) is currently around 80 trillion US$. (That's a US trillion, a British billion.)
Wouldn't the GWP be all the money the world economy turned over in a given period of time? How is that related to M2, M3 or whatever?
When you got some money on your account or under your mattress, it counts for the M's, but doesn't do anything, so doesn't count for the GWP.
You're right. Monetary Base (MB) is probably the best bet to figure this out. MB of the US is supposedly $3,736,101,000,000. What about the world?
The first question is which one of the M's to take (M0, M1, M2, M3,M4).
I guess it should be either M2 or M3.
M0 and M1 would be too narrow, I'm pretty sure. So let's go with M3 (or maybe even M4), because this somewhat resembles the use of BTC and shows which part of the economy BTC could theoretically substitute.
I googled the world M3 for 20 minutes, I couldn't find it.
But $75 Trillion is what I remember having read somewhere as well - that is why initially I thought you were on the right track.
It's probably even higher than governments admit, with all the money printing (making 1BTC in our example worth more) - for example, the US government stopped reporting the M3 8 years ago.