alt Hacker News> it assumes rental price and housing costs are somehow linked when in reality asset prices have far outstripped rent
It's pricing the cost of shelter. Renting a home is buying shelther. Buying a home is buying shelter and buying a financial asset. OER is the way you separate the last two components. Otherwise, you'd have to only look at rents to determine housing prices, which would be rubbish in a country where most households live in homes they own.
Suppose you want shelter. It used to be that you could buy a house for a reasonable price and move in. But now that's unaffordable, so instead your have to pay rent. In CPI thinking these are equivalent forms of shelter, but I bet if you asked most Americans, they would not agree with you.