[bombcar]

Even then I’m not sure how much it affected the poorer people, since you still had to overcome the standard deduction (lower, sure).

The deduction on mortgage interest now mostly only affects the well-off because the standard deduction for married filing jointly is so high.

[bonton89]

The the 1980s the deduction for mortgage interest would have been significant, I suspect most people itemized then. And the huge standard deductions we have now are a fairly recent tax change.

[bombcar]

It was 3400 for a married couple in 1980, but yes, many more people deducted mortgage interest until 2018 when the standard deduction nearly doubled.

Many people didn't math the interest deduction correctly - only the amount over the standard deduction should be counted, as you'd get the standard deduction anyway. Can vary depending on SALT and charity donations.

[bonton89]

Yes, real estate tips always seemed full of self serving nonsense to me and usually talked big about the tax savings. But with my modest house and mortgage I calculated that even at the start of my mortgage I saved a whopping $800/yr on taxes with deductions versus the standard deduction. I spent well more than that on furnishings and repairs every year. And that tax advantage (for me) disappeared entirely after maybe 5 years or something.

For a long time I would read money saving tips articles and a tip that frequently came up in these and in pro real estate pieces was that paying a single extra mortgage payment per year would let you pay your mortgage off 12-15 years early.

When you did the math you realized it was bogus. As near as I can tell, this actually was true for one brief period in the 1980s when mortgage rates were at their zenith. Articles were written about this amazing tip well into the 1990s before the BS was transcribed to the internet and then repeated well into the super low interest rate era where it wasn't even close to being true.

Of course it wasn't even really true in the 1980s either. Once interest rates went down you'd have been wise to refinance at the newer lower rates instead of prepaying the mortgage as it would improve your cash flow and lock in the savings. So in reality, it would have only made sense if interest rates had stayed at that same high rate for the whole length of the mortgage!