How important is protecting the mortgage-interest deduction (MID) for Tennesseans? Very. 

Of approximately 1,660,000 owner-occupied houses, 995,000 or 59.9% had a mortgage in 2014**, while 443,600 Tennessee taxpayers claimed a deduction for mortgage interest. The total deducted was $3,562,440,000. The average taxpayer claiming the MID subtracted $8,050 from taxable income. At a marginal rate of 25%, the average taxpayer saved $2,010. Total tax savings from the MID in Tennessee was $890,610,000.

Digging a bit deeper, 509,300 Tennesseans claimed a deduction for real estate taxes, deducting $1,389,843,000. The average taxpayer claiming the real estate tax deduction subtracted $2,750 from taxable income. At a marginal rate of 25%, the average taxpayer saved $680 as a result of the real estate tax deduction. The total savings from the deduction in Tennessee was $347,460,750.

If the MID and real estate tax deductions were eliminated, the loss would not be a one-year event; it would affect homeowners every year. The present value of lost savings could total $31,745,403,800. The value of all owner-occupied real estate in Tennessee was $303,266,543,000.

If the lost tax savings are fully capitalized into the price of houses, the average decline could be 10%. The median-priced home in Tennessee was $143,200; a decline in value as projected could mean a value loss of $15,000 for the typical homeowner.

**all stats are as of 2014. Sources include: Internal Revenue Service, American Community Survey, National Association of REALTORS®; All calculations are by the NAR Research Division, July 2017.