BBCWatcher
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You might have it exactly backwards. Allow me to illustrate....Basically, government can save millions of interests if CPF is not compounded monthly.
Scenario #1: You deposit $1000 on January 1, 2017, into an account with an Annual Percentage Yield (APY) of 5.0% with interest computed monthly and compounded annually. You withdraw the $1000 plus interest on July 1, 2017 (exactly 6 months).
Scenario #2: You deposit $1000 on January 1, 2017, into an account with an APY of 5.0% with interest computed and compounded monthly. You withdraw the $1000 plus interest on July 1, 2017 (exactly 6 months).
Question: Which Scenario provides a bigger withdrawal amount?
Answer: Scenario #1. In Scenario #1 you would end up with $1025.00. In Scenario #2 you would end up with $1024.70, or 30 cents less.
The key here is the Annual Percentage Yield (APY). Fixed deposits in Singapore are (generally) calculated as in Scenario #1, as with CPF. But theoretically a bank could advertise a 6 month fixed deposit compounded monthly with an APY of 5%. And actually the nominal interest rate applied in that case would be 4.889%, and (with monthly compounding) that'd generate a 5% APY. If you hold the funds in your account for exactly one year, no problem: APY 5% = APY 5%. But few people do that in a demand account, which CPF is, really (albeit long-term). So if you're comparing accounts with equal APYs, the annual compounding is better than the monthly, and the monthly is better than the daily.
Now, if the nominal interest rate is 5%, and 5%/12 is applied each month, that beats an account with a 5% APY compounded annually. But that isn't what typically happens when savings products are marketed and compared, because they're generally compared on the basis of APY.
