(Not OP) I first read about this in The Bitcoin Standard by Saifedean Ammous, the first 2/3rds of which, incidentally, is a history of (in his view) bad money.

(Not OP) I first read about this in The Bitcoin Standard by Saifedean Ammous, the first 2/3rds of which, incidentally, is a history of (in his view) bad money. There he writes how the value of the gold (aureus) and silver (denarius) coins in circulation then was gradually eroded by clipping and debasing the precious metal content in the years leading up to the collapse and he supposes that this had a significant impact on the collapse of the economy and then the empire itself. He links coin debasement to food shortages, as market prices rise to compensate for debased currency. Price caps set by the Roman government stop food producers from being able to adequately profit from their labour, so food shortages occur, then civil strife and eventually collapse.