[zenithd]

> it is force of law that prevents large scale arbitrage of the form in this article.

This is actually exactly analogous; many people don't realize that the status quo of "multiple denominations" have ancestral ties to bimetallic currencies of the sort covered in this article.

It would have been difficult for Henry III to de facto outlaw smelting of gold coins because the scale of the gold penny's distribution was much smaller (making attribution of a smelting operation much harder), and because the ability to surveil this sort of activity was severely limited by geography.

But melting down US pennies is de jure illegal (nb: only since 2007 [1]) and the number of pennies you'd need to smelt down in order to justify the effort would probably make the sourcing operation noticeable to authorities.

[1] https://www.usmint.gov/news/press-releases/20061214-united-s...