From NBC News:

“We estimate that houses today, depending on the metropolitan area in question, are from 250 to 1,000 square feet larger than they otherwise would be,” a forthcoming study by the R Street Institute determined.

The richer the homeowner, the greater the benefit, it found. “We also find that major metropolitan areas on the East and West coasts get the most tax relief from the mortgage interest deduction,” the study said…

…Ultimately, the R Street Institute study comes to a sobering conclusion: “For millions of families who struggle to afford a house, these tax breaks offer no relief at all.”

Featured Publications