Heard about this in Abundance: How We Build a Better Future.

Homes can’t be both investments and affordable enough for everyone to own.

For a home to be a good investment, its price has to increase. For that to happen: You have to control how many homes can be built 1. If supply is low then price increases 2. With zoning permits and laws you can control which type of homes can be built which would control who can afford those homes