The third person in the analogy is the government, who demands payment specifically in dollars and who can use a remarkable amount of force if you don't pay.
Hehe, I interpreted the comment as being in the absence of government, and in terms of how older societies used to pay a third party protection money (effectively a tax) to protect them from thefts etc from others, but who would intimidate, steal or destroy property if the money wasn't paid.
You could argue that government isn't much different to a mafia, except that modern taxation is generally more transparent, fairer, impartial, and perhaps more considerate to the people with the least money. Also, they generally don't use force to enforce taxation, only the threat of a prison sentence.
You could argue that government isn't much different to a mafia, except that modern taxation is generally more transparent, fairer, impartial, and perhaps more considerate to the people with the least money. Also, they generally don't use force to enforce taxation, only the threat of a prison sentence.