answer:I am no economist, but I will give it a shot :) I dont think they would be able to do that. The UN is not a nation backed organisation in the sense that there is a pool of ressources that they can draw on to support a monetary system, unless it was a consensus between the member nations. The reason that the EU can do it is that they are formost a economic union, and thus have a lot of support in such a venture from its members (albeit declining a bit after the Euro zone economic trouble). The economic ramifications would also be big, since each nation would have to recognize the validity of such a currency, set its value relative to its own and much more. Take the dollar, it has earlier been based on the gold standard, where a dollar was wirth an fixed amout of gold. That was a stable, fixed value, and something you could compare to. Nowadays its more based on the issuing nation’s economy and thus the relative value is fluctuating based on the strengt of the U.S economy. To start a worldwide economy would probably disrupt quite a lot of national economies, leading to issues akin to what we have seen in the Eurozone. This is just me thinking about this over morning coffe, so maybe somebody with more knowledge may have a better answer :) OH.. And I would call it Galactic Credits, just for the added SCi-Fi feel :p