Currently, the game does some weird things with loans. It charges you an interest rate on an amount of money borrowed, but never changes whether you owe $1,000,000 or $10. In reality, banks/lenders charge an interest rate against your principal, so if you owe $1,000,000, your payments are much larger than if you’ve paid down that loan and only owe $1,000.
Also, it is a bit dubious that you can set your payments to zero as though any lender would let you just pay nothing against the money you’ve borrowed from them. There should be a ‘Minimum Payment Due’ on every outstanding balance or you incur fees on that balance.
Additionally, it would be great to have a variable APR. This would add an extra layer of depth to the decision making tree of operating and expanding your empire. If you want to take a fat loan to open some more businesses but go to the bank and find the current interest rate is 9.5%, you may want to wait a while and hope for the much better (less expensive repayment) rate of 3.5% (or whatever).
It just feels like the current system is a bit too dumbed-down and really not reflective of the way things work in the real world.
In the US, negative interest rates usually occur only at the Federal level (as a way to get commercial banks to borrow more money from the government to lend to consumers, small businesses, etc) but rarely, if ever, get charged to consumers depositing their money into their local bank. I understand the utility of it in the game as a way to keep players from hoarding their cash, but frankly, if it’s going to exist, I think it should be a lot more onerous and should probably be tied to the amount of cash you are sitting on (the more you have, the more you are charged). I haven’t tested it, so maybe it already works like that, but it feels like by the time Uncle Fred mentions it, you usually have enough money that you don’t really miss that 1.5% (or whatever it is). Now, if I were losing 10% or more, you can bet I’d be investing it in stocks and new businesses (or just gambling it away, buying cars and yachts, etc).