That's the thesis advanced in this post at Trulia's blog, with obvious differences among housing markets. In the Chicago metro area, for example, Trulia estimates the monthly average cost of ownership at $821 and the monthly cost of renting at $1,628 – a 50% difference.
Trulia's approach is based on what appears to be, on the surface, a methodologically sound approach to calculating the financial costs of owning vs renting for comparable homes.
Get out in the market, however, look for homes that are being offered both for sale and for rent in the MLS, and you're likely to find that Trulia's numbers are laughably incorrect.
I find myself often doing the rent vs own analysis on MLS-listed homes – and nine times out of ten the analysis clearly favors renting.
The take-away: dig into the numbers on specific properties that you'd actually be willing to live in rather than deciding to buy based on the assumption that you'll be financially better off than by renting.