There are several ways that you can reduce your tax in Hong Kong: Rental Reimbursement / Home Loan, Charity, Educational Expenses and MPF. Paying into the MPF will help reduce your tax by offsetting the contribution against your income for Salary/Tax purposes.
This means that when compared to any other type of saving, you are not paying any tax on your MPF savings. This means that you can still pay the same amount into your savings (MPF) and it can give you up to 17% more to put into your account.