First, people fail to understand that to obtain a debt subsidy, you must have debt. You must be making an interest payment on this debt in order to qualify, and they you get to reduce your tax burden by a small percentage of the interest amount. In short, you are paying a dollar to save a quarter. There are people who actually seek to maximize their interest payments in order to increase this subsidy. This is really, really foolish. Anyone out there who believes it is a good idea to spend $1 to receive $0.25 in return, please send me as much money as you wish, and I promise to send back 25% of it.

Realtors try to con people with the “throwing your money away on rent" argument. Homeowners buy into the fallacy. Interest is the rent on money. You throw away money on interest just like you throw it away on rent. In fact, people who overpay for housing throw away more money on interest than renters do to obtain the same property, even after the tax subsidy. The only argument one can make for paying extra interest is if you are receiving a return on that investment through property appreciation. We all see how that is turning out.

The main reason the benefits of the home mortgage interest deduction are overestimated is because people forget they must give up the standard deduction in order to obtain it. This is one area where tax policy can have hidden and indirect impact on housing. Changes in the standard deduction greatly impact the benefit of the home mortgage interest deduction. As the standard deduction is increased, the positive impact of the HMID is decreased. Basically, if you want to figure out your real tax benefit, take your highest marginal tax rate and subtract 10%. That will be a much closer estimate to reality. This reduction is caused by losing the standard deduction.

In fact, if the standard deduction were doubled, the average American holding a $150,000 mortgage probably would not bother itemizing to obtain the HMID because it would be of no tax benefit at all. This would certainly simplify people’s tax returns. A higher standard deduction is also a boon to renters who do not have the option of obtaining the HMID.

Another facet to the HMID is the cap level. Currently mortgages up to $1,000,000 are eligible for the deduction. Does anyone think this is right? Do you realize you as a taxpayer are subsidizing $1,000,000 mortgages? When the GSEs were set up, they established a conforming loan limit. The reason they did this is because they are mandated to subsidize mid and low income housing. Why is the limit on the HMID any higher than the conforming loan limit from the GSEs? Why are we subsidizing high income borrowers?

If we were to reduce the HMID cap level to $500,000 and adjust it by the CPI going forward, we are still subsidizing relatively high income borrowers ($500,000 is still almost triple the median home price in the US). A reduction in this cap would have the same impact as the lower GSE conforming limit is having: it would lower prices at the high end by eliminating the subsidies.

IMO, the government has no place in subsidizing house prices that are well above the median. One can argue that the government should not be subsidizing anything in housing, but the low and middle income subsidies are here to stay. If we raise the standard deduction and lower the HMID caps, we can greatly reduce the impact of the HMID and the cost we pay for it as taxpayers. This would have the effect of lowering prices on more expensive homes, but it would help stabilize the lower end of the market. That is what the market needs right now.