Treat EXACTLY like an interest rate, except deduct the "i":
i = .02/12 ; n = number of months
interest: 100(1 + i)^n
fee: 100(1 - i)^n
Let's say I have 100 and it's in an account that is charged 2% per year.
This fee deduction is taken out every month.
Each month, would the fee be:
1.) CurrentAccountValue * (.02/12)
2.) CurrentAccountValue * ((1.02^(1/12))-1)
3.) Something else?