The article discusses the home price to income ratio in the US, which has historically been around 5 times the yearly median household income but exceeded 7 during the housing bubble of 2006. The ratio is calculated using the S&P/Case-Shiller Home Price Index and median household income data. The article also touches on the importance of considering mortgage rates when assessing affordability. The current data suggests that home prices have become less affordable, leading to a decline in real home prices.