From the cited source:
Stalin is an uncommon figure in modern economic history: a dictator with absolute power who also controlled one of the largest economies in the world. Since it is virtually impossible to separate Stalin's wealth from the wealth of the Soviet Union, this combination has led multiple economists to nominate him as one of the richest people of all time.
...
While that money didn't belong directly to Stalin, he had the ability to leverage blah blah blah peepee poopoo
Neolib ghouls are absolutely wild.
I can debunk those economists.
My source of choice? The Central Intelligence Agency. When? In the 1950s. Shortly after Stalin died. What is the nature of this document? A declassified internal memo, not intended as propaganda, but as candid discussion between agency officials.