Shannon: Housing subsidy

In our class Housing and the Community, Shannon - our professor, mentioned that the biggest subsidy to the housing market is not to the poor, which is how most of us perceive subsidy: Public/social/affordable housing for the poor, who get 'massive' discounts on their living expenses. Most of the times the US provides vouchers to poor renters to pay for the remainder of cost over 30% of the renter's income. 30% of income is the 'affordable' price for housing. 

Contrary to this belief that most housing subsidy goes to the impoverished population, Shannon informed us that the mortgage repayment tax breaks for home-buyers are by far the biggest federal housing subsidy. It makes sense if the majority of the population in the United States lives in single family housing and they get a mortgage to buy it, they will get an income tax break for that mortgage.