Back to a more abstract economic view, it looks like Concord essentially prints money. We blow shit up, they pay us. We run a mission, we get paid. Etc.
But where do they get the money? Are they in fact just printing it off? This is usually poor economic policy.
When mission agents pay us for doing whatever, are they paying us with ISK that Concord just gives them, or do they have to exchange their own currency to pay us?
So, theory: Concord does not simply print limitless amounts of isk. Concord was put together by the empires and is funded by the empires. Concord takes money from the empires, converts it into its new, universal currency for people who no longer acknowledge empire boundaries and cba to change out their money each time they cross a line.
Thus, there is an exchange system for ISK to [empire] currency. This exchange does not exist within the game interface, but given that mission agents can pay us, given that we have to pay isk for station services which must then be converted to their currency to pay for the labor that builds our ships, etc...
It just doesn't make sense for Concord and ISK to exist in a pure vacuum. There has to be an exchange to baseliner (or at least government) currency.
I'm not sure what I'm arguing anymore, does that make sense? bloody workday has scrambled mah brains.