3. 所得税减免政策

　　主要内容

　　美国政府为了刺激房市，推出政策给购房者提供税收优惠，经济学家对此进行反驳：第一，银行的钱都借给个人买房，造成没有商业贷款可以贷了;第二，房价飙升，如果只是对需求(demand)补贴，而供方(supply)没有弹性的话，房价会升高。第三，加大贫富差距，富人交的钱更少了。

　　参考文章

　　At first blush, the mortgage interest income taxdeduction seems like a greatthing. You get to deduct your mortgage interest from your income. This savesyou money and encourages homeownership nationwide (believed to produce positiveexternalities such as crime reduction, community, etc.).

　　But beneath the surface, themortgage tax deduction disproportionately benefits the wealthy and createsperverse incentives and market distortions that are plainly bad for America. Ideal with these issues one by one:

　　(1) Good for the rich: since theUS tax code allows the deduction of mortgage interest directly from yourincome, those that benefit the most are those with the most income. The verypoor cannot afford to buy a home, so they do not benefit at all. Poorhomeowners benefit very little because they do not pay much in income taxes.But the wealthy receive huge tax breaks from the interest on their jumboMcMansion mortgages.

　　(2) Perverse incentives: becauseof the huge mortgage interest tax break, high income earners are then encouraged (and subsidized) to buy ever more expensive mansions and borrow even more moneythrough ever larger jumbo mortgages.

　　What to Do Next

　　The rational policy choice wouldbe to eliminate the mortgage tax deduction. The federal government can stillencourage homeownership (distinguished from mansion-buying) by instituting aHousing Tax Credit. The credit could be cost-neutral and take the average costper family of the current deduction, and give that amount out as a tax creditto any family or individual who wishes to purchase a home. A standard creditwould make sure that regardless of a family's income they would receive thesame nominal incentive. This would provide more incentive for poor people tobuy a home (the credit would likely be worth more to them than the currentdeduction) and waste less taxpayer money on subsidizing the mansions of thewealthy. Moreover, such a policy could potentially spur homeownership amonglower-income families, which could help us dig our way out of the housingcrisis. Let's hope the next president has the foresight to do something aboutthis