Assume that $10,000 is deposited in a savings account at the beginning of
year 1 earning 5% and that $1,000 is deposited at the beginning of each month
into the same saving account also earning 5%. However in year two, the bank
changes the interest rate to 3%, and in year 3 changes it 2.5%... I want to
be able to generate an effective yield rate at the end of each year for this
case. The rate function can't do it because of the non-level premium flow.
Is it true that the XIRR can't do it because I don't have a negative balance?
If both of my statements are true - what are my options?