"... So when we conduct our scenario analysis, we see that a simple increase in the mortgage rate from 5 to 7.5, we would expect to see a 13% decrease in housing prices over three years. The worst case scenario at 95% would be a 45.8% drop. If inflation really showed its ugly head and rates go to 11.75%, we would expect a 30% drop in real housing prices with a worst case scenario of a 45% drop..."
http://www.economypolitics.com/2010/07/correlation-of-mortgage-rates-with-real.html