AL Econ Marco Does money supply= purchasing power?

No, there is no relationship between money supply and purchasing power...

Roughly, there is no definite meaning of money supply. And there is only 3 kind of money supply - M1, M2 & M3. You can see my another reply. M1, M2 & M3 can fluctuate seriously by the depositor depositng in different kind - current a/c & NCD.

And the purchasing power is influenced by the general price index. If the price index is higher than the interest rate, that means the puchasing power is depreciated.