Credit is complex when it comes determining interest and payments. Governments have it easier then people when it comes to loans, but not all are the same. For galciv there was a interest rate modifier for the korx's and neutral civs, but that was it.
So when I was listening to my dad talk while we were driving with the fam ( he loves driving ) credit and interest rates came up. And I thought...that would be so awesome and realistic in to have in galciv. That would add a ton of strategy and plotting in the economy area. For example.
1. Nations that take loans and pay then off on time or before increase there rating and lower their interest for hurrying production. Hurrying production also would count as a transaction and lower the cost.
2. Having a big economy gives you a better credit rating.
3. How big of loan you can take.
4.race points can be used to better starting credit/modifiers.
5.planets/quality*(making planet quality a factor might be dumb), resources, and ships can can be used as collateral for loans and buying. So if you want money you can just put some improvements or ships or up as collateral. Whatever you give will be worth more than the loan but will get better with your credit.
6. Buy your opponents debet to feed your pockets and stay out of war. If the torian got a expensive battleship for 2000 credits. And used a planet as collateral, for the time it takes for the income and production to equal the designated value, you can build ships there until 2000 pro/creds have been made not factoring in interest. But since the AI will be a perfect always leaning super genius it won't find itself doing this as much as we probably will.
7. And the most important thing is to have fun 
there are oddities in here that need to be worked out. So more input would help. Add ideas, take away ideas, remake it all or hate it all, it okay with me.
DARCA