I'm not sure. According to the National Association of Realtors, the median house price in the US is $170,500. The most recent American Housing Survey data from 2008 shows median rent at $ 808 per month, and the CPI-Rent index is essentially flat since 2008. This means the cash flow cost of renting is $9696 per year.
If we assume the mortgage interest rate on a 30-year fixed rate mortgage is 4.5 percent, the cost of home equity is 10 percent, a buyer puts 20 percent down on a house, property taxes are one percent of house value, marginal income tax rates (state and local) are 25 percent, maintanence costs are one percent per year, and amortized closing costs are another one percent per year, the cash cost of owning is $12,162 per year.
But the median rental unit is 1300 square feet and the median owner unit is 1800 square feet, so owning the median owner unit costs about 10 percent less per square foot than renting the median rental unit. This means house prices could fall and, in some places at least, still leave the owner better off than renters.
Neither renter nor owner markets are national, but I am hard pressed to think of a time when owning on a cash-flow basis looks so reasonable relative to renting.