What I can tell is from my experience and my sisters. I don’t know what the data is based on, but the household income in the professions I know of (my sister’s family and mine)- has not gone up more than 25% nominal.
The houses though, on the other hand have doubled – at least. Same house, sales price in 1999 compared to now. My sister being almost 10 years older got in 1999 a nice 1989 built, 2100 sqft house in a great school district – for under 400K. Now that house based on all comps is just shy of 800K (my sister is in Irvine).
With our salaries which are about 20% above what they had in 1999, I can afford a 400-500K but certainly NOT a 700K house.
Quod erat demonstrandum.