The so-called mortgage interest tax deduction generally means that when personal income tax is levied, the interest generated by mortgage is deducted as a pre-tax deduction item, and personal income tax is deducted from the deducted income.

Suppose that buyer A buys a set of ordinary houses with a total price of 2.5 million yuan in a first-tier city, and pays down 500,000 yuan, leaving 2 million commercial loans for 20 years, and the monthly repayment amount will reach 13927.74 yuan, of which 5594.40 yuan is interest expense. The pre-tax monthly income of Buyer A is 20,000 yuan. According to the current tax policy, after deducting the four gold and tax base, the taxable income is 2459.02 yuan. However, if the interest cost of the mortgage loan,