[quote author="meme" date=1243567990][quote author="awgee" date=1243537428]What you "see" on the graphs does not determine correlation. Correlation is determined by statistical relevancy. Simplistically, if one third of the graph correlates and two thirds does not, there is no statistical relevancy and therefore no correlation. You can not pick and choose which portion of the graph you use and which you do not.
And if you try to say that a portion correlates and a portion does not because of other factors in the portion that does not, then overall there is no correlation. You can not just pick and choose to include other factors during some years and not during others. You can make anything correlate with anything if you pick and choose.
Again, by all logic, one would think the two inversely correlate, but I have seen the statistical analysis based on charts such as these, and they do not. It seems there are just too any other factors influencing home prices.</blockquote>
I agree with everything you're saying. However, I can come up with a logical reason why there is no correlation.
Low interest rates do not exist in a vaccuum, they happen during times of low inflation. High interest rates happen during times of high inflation.
Low interest rates should encourage higher housing prices. However, low inflation has the opposite effect, as people don't want to buy a house which won't be going up in value much at the same time that their salary won't be going up much.
High interest rates should lead to low housing prices. However, high inflation has the opposite effect, as everyone wants to buy a house when inflation is sending the price of everything, including housing prices, up. Also, if your income is rapidly going up due to high inflation, any house you can manage to barely squeeze into being able to pay for today, you'll easily be able to pay for in a few years. This is why people were still buying houses at the peak of inflation 30 or so years ago when mortgage rates were 15%.
So inflation and interest rates cancel each other out.</blockquote>
There are two variables that show strong correlation with home prices: income and rent. The only time prices diverge from these two variables is during a housing bubble, and then during the crash, prices return. Up until the early 1970s, the correlation was very high, but since we began the housing bubble merry-go-round in the late 70s, the correlation has broken down. It recalibrates at the bottom of every correction. That is why economists point to these two variables as the determinant of fundamental value.