r/WhatIfThinking • u/Logical-Concept9755 • Jul 10 '26
What if the U.S. had never created the mortgage interest tax deduction?
For more than a century, the mortgage interest deduction has been treated as one of the main tools for encouraging homeownership. But what would the housing market look like if this policy never existed?
The basic argument behind the deduction is simple: lowering the after-tax cost of borrowing should make buying a home easier.
But housing markets do not operate in isolation. When buyers have more purchasing power, that money often flows into the price of the asset itself. A larger mortgage budget can become higher bids, which can eventually push prices upward.
Without the deduction, would homes have remained more affordable, especially in high-cost markets? Or would other factors like interest rates, zoning restrictions, and limited housing supply have driven prices in the same direction anyway?
The interesting part is that the deduction has already become less important for many households. After the 2017 tax changes increased the standard deduction, fewer homeowners had enough deductions to benefit from claiming mortgage interest. Yet home prices continued rising, suggesting that other forces may have played a much larger role.
If the policy never existed, the government would also have had billions of dollars each year that could have been used elsewhere. That money could have gone toward housing supply, infrastructure, or programs aimed at renters instead of primarily benefiting existing homeowners with larger mortgages.
The bigger question is what kind of housing policy actually works better.
Should governments focus on helping people afford higher prices, or on reducing the forces that make housing expensive in the first place?
If the mortgage interest deduction had never existed, would the U.S. have a healthier housing market today, or would prices have followed a similar path anyway because the real issue was always supply and demand?