Reversion to the mean is an accepted asset bubble principal, among those who understand bubbles. There are always those who say this time is different or we’ve reached a new permanently higher plateau. Every bubble in history has reverted to the mean. Anyone who has any doubts, like sduuude, ought to read up on the topic. There are excellent books on bubbles.

In my charts, I went to December 1999 to make my trendline, because I wanted to see the effect of the bubble, which started in 2000. So for 2 full years after the new tax laws were enacted, home prices did not change. But what had a big effect? Low interest rates, looser underwriting guidelines. But as soon as interest rates were lowered, poof, up went prices.

To me, the mean is the period from 1968 to Dec 1999. Over 3 decades of data, all in a straight line more or less.