One that reflects the mortgage payment which is influenced by the interest rate.
For example,
Loan—-Interest—-Payment—-Year—-Case Shiller
$400000 — 6% — $2400 — 2000 —— 100
$400000 — 5% — $2150 — 2009 —— 120
Modified Case Shiller = 120 * (2150/2400) = 107.5
107.5 is much smaller than 120. Of course, assuming that it is adjusted for inflation (2009 dollars).
I am sorry if this has been done already. I have been looking for something like this but can’t find anything.
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