The graphs are based on the Case-Shiller – FWIW this is their description of how the values are calculated.
This is house price inflation.
The Case-Shiller Index, by comparing the sales price of a house in the current month to the price of the same house when it sold previously, tracks how many more dollars it takes to buy the same house over time, thus tracking the purchasing power of the dollar with regards to houses in various markets. This makes the index a measure of local “house-price inflation.” When the index shows that prices in Los Angeles shot up 188% in 19 years, despite the plunge in the middle, it doesn’t mean that houses have nearly tripled in size or opulence, but that in that metro, the dollar’s purchasing power with regards to houses has gotten crushed.
