The Case-Shiller Index operates on a “three-month rolling average” basis. And the price data is collected from public records. So the release today, titled “April,” was the three-month moving average for deals whose data became available in the county deed recorders in February, March, and April.
There is also a time-lag between when a deal closes and when the data becomes available in the county deed recorders.
So what the Case-Shiller showed today were closings that had occurred in prior months and that became available in the county deed recorders in February, March, and April. This included some of the deals that closed in January and excluded some of the deals that closed in April.
This is not a secret. S&P publishes the methodology. And reporters should have studied it before reporting bull-malarkey and misinforming their readers, many of whom paid a subscription to be misinformed.
So, what the national index told us today is nearly all based on home prices before the impact of the pandemic. It will be another three months – the index to be released on September 29 – before every month in the National Case Shiller Index’s rolling three-month average fully reflects home prices of sales that closed since the beginning of the lockdowns. Each month will get us a step closer. And even then, it will take a while because house price data is sticky and moves slowly. So be patient.