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 prison

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.