A study this year by the Tax Policy Center of the Brookings Institution and the Urban Institute noted that the mortgage deduction was worth just $91 a year to families earning less than $40,000 — and $5,459 a year to those making more than $250,000. The U.S. homeownership rate (66.9 percent) is about the same as Canada's and is lower than Australia, Ireland, Spain and Britain's, even though "these countries provide far less government support for homeownership," Michael Lea of San Diego State University wrote earlier this year.
http://www.usatoday.com/money/economy/housing/2010-08-18-housing18_ST_N.htm