> But once cigarettes were banned, prisoners needed a replacement currency and the 'mack' was deemed to be the best choice because it was worth roughly $1 at the commissary and pretty much no one wanted to eat it.

> As one prisoner notes in the Wall & Broadcast video below, the 'mack' was also "inherently inflationary" because its supply was limited to 14 macks per week per inmate....

I stumbled on this economic curiosity by way of an SBF article on his adventures in prison living. The curiosity? Canned mackerel is "currency" in some prisons. And there are some interesting details behind why it has become currency rather than cuisine.