Analysts: Industry overstates impact

Mortgage

that leaves most middleincome households untouched.

With the mortgage interest deduction, households realized tax savings of $83 billion in 2010, according to figures from the Reason Foundation. Nearly $65 billion, or 78 percent of those savings, went to households earning $100,000 or more.

There is a range of ways to increase tax revenue by aiming at higher earners, some less comprehensive than others. For instance, the interest deduction relating to second homes could be ended. Also, the cap on mortgage debt eligible for the interest rate deduction — currently $1 million — could be reduced. There are broader approaches, too. In its proposed budget, the Obama administration plans to focus on top earners.

The administration suggests capping deductions at 28 percent for high-income households, those earning more than $250,000.

Under the current rules, a high-earning household deducting $20,000 in interest payments would probably apply a 35 percent rate to that amount and receive $7,000 in tax savings. The Obama budget aims to limit that tax saving by capping that rate at 28 percent. If that rate were applied to $20,000 of interest payments, the saving would fall to $5,800.

The United States would capture the difference. Over the next 10 years, that 28 percent cap could increase tax revenue by $584 billion, according to the Treasury Department.

Separately, the Obama administration also wants to limit high earners’ deductions by letting certain Bush-era exemptions expire. All together,

One argument against a cap is it could reduce demand for housing.

the Treasury Department thinks it could raise $749 billion over 10 years by limiting deductions for higher earners. That is substantially more than the $684 billion it thinks it could raise from increasing their tax rates.

One argument against curtailing the mortgage deduction is that it could reduce demand for housing, depressing home prices when the housing market is still somewhat weak. The National Association of Realtors believes a removal of the deduction could reduce property values by 15 percent, according to a presentation last year from its chief economist, Lawrence Yun.

Other analysts say they believe the housing industry overstates the potential impact.

With several forms of government subsidy also supporting housing, it is hard to single out the effect of the mortgage deduction. At the most, the Reason Foundation estimates, the deduction may bolster house prices by 3 percent.

Since any deduction cap is likely to aim at higher earners, expensive houses would be most affected. But big-ticket homes appear much more resilient to shocks than lower-cost dwellings.

Given the apparent sturdiness of the higher end of the housing market, politicians may decide there are few risks in effectively capping mortgage deductions for high earners. Limiting tax breaks in a way that could reduce mortgage relief would be a change for Washington, which has done so much to support housing.

Nick Kasprak, an analyst at the Tax Foundation, said that up until recently he didn’t expect to see a cap on deductions.

“But now,” he said, “it seems both parties are open to pursuing this strategy.”