Assuming a purchase of $350,000 or a median home currently (Here), the potential borrowers seeking a 90% loan (currently regulators and Congress are debating an 80% loan to value maximum, although it is likely this will be negotiated higher) then the following analysis would back into the necessary income to obtain a qualified residential mortgage through Fannie, Freddie or the FHA. The loan applied for would be $315,000 at a currently offered interest rate of ~4.75% on a 30 yr term. The Principal and Interest Payments would be $1,643/mo or $19,716/yr. Taxes based upon Leonetti’s analysis would be $5,065 per yr before the increase and $6,025 after. I am assuming insurance would run approximately $900/yr. So the total annual residential expenditures would be $25,681 and $26,641, respectively. This would mean that the borrower would be required to have a gross income of $91,718 and $95,146, respectively, based on a front end debt ratio of 28%. Notice that the income required jumps $3,428 or 3.7% because of the proposed increase in property tax. This means that fewer potential buyer/borrowers will qualify and will either be unable to finalize the purchase or be required to put more money down. Given that the median income in City-Data for median households with mortgages and apartment or rental households without mortgages is $74,824 and $44,788, respectively (Here), then such a tax increase will shrink an already small pool of potential home buyers who must rely upon financing to qualify.