That doesn't work because it's not only general population growth that's driving housing shortages in cities, it's that people are moving to popular cities from

That doesn't work because it's not only general population growth that's driving housing shortages in cities, it's that people are moving to popular cities from less popular places. San Francisco doesn't have a housing problem because too many people had babies in the last 10 years, it has a housing problem because way more people want to move to San Francisco from other US cities than it can support. Another way to think about it: Japan's population is flat or declining depending on the stat you look at, but Tokyo is still increasing in population.