Impossible to say for sure without seeing the exact methodology and the data, but there are probably many other issues with this "study". * taking data for the

Impossible to say for sure without seeing the exact methodology and the data, but there are probably many other issues with this "study". * taking data for the past year (or for a few recent years) and extrapolating it to 30 years, instead of actually getting the data for the last 30 years * hindsight bias: 30 years ago you didn't know whether it would be better to buy a house in San Francisco or Detroit. * comparing returns on a risky, leveraged investment (buying a house) with returns on a low risk investment ("interest earned on any money renters saved").