Here is a study by three researchers out of California that asked Americans to predict the impact of a supply shock on various things, such as durable goods, commodities, labor, trade, and yes, housing.
For basically all of these items, people tended to answer correctly. Usually by a factor of at least two to one. In other words, when asked what reducing the supply of new cars would do to the prices of used cars, the majority of people responded saying that it would lead to an increase in prices.
However, when asked about the impact of a 10% increase in housing supply, about 40% said that it would cause prices and rents to rise. Only about a third believed they would fall (the correct answer). This is fascinating because it shows that housing seems to be an outlier. Most people don't have the same intuitive sense.
Why is this? Well, one commonly held belief is that building market-rate housing leads to gentrification, and that this ultimately leads to the displacement of existing residents. This might have been why some people responded saying that new housing will cause an increase in prices and rents. It'll lead to all housing going up.
However, there's research to support that this isn't the case. The problem isn't outward displacement following new market-rate housing. The greatest driver of gentrification is actually "exclusionary displacement", which is the inability of people to move into areas because of a lack of housing. (This study was based on 2010-2014 housing data from the UK.)
The thing about housing supply is that it relieves pressure across the entire market. Instead of a high-income person buying an old home to renovate (and causing outward displacement), they can instead choose to buy a new home (and not cause any outward displacement).
By doing this, they also leave behind a home that can then be absorbed by lower earners. One US study found that for every 100 new market-rate homes that are built, somewhere between 45 and 70 people move out of a below-median income neighborhood.
It is for reasons like these that, time and time again, increased housing supply has been shown to moderate home prices and rents (see above regarding Minneapolis and the Midwest as a whole). So if you're worried about the cost of housing, the answer is to build more. And if you're worried about gentrification, the answer is also to build more.
Our intuitions are telling us that this is true for most things. But for whatever reason, housing feels different. It's not, though.
Source: The charts and studies in this post are from this great FT article by John Burn-Murdoch.
