While the article is interesting, there is one dynamic it missed: tech debt. Starting around 1975, housing supply stopped keeping up with the growth of housing demand. It picked back up fifteen years later, around 1990: https://www.brookings.edu/research/the-goldilocks-problem-of... (But that is on a national level: in the West, in comparison, housing growth hasn't been sufficient to house the new households formed a…
If cheap housing is expensive housing built 30-100 years ago, we should have had decades and decades of delapidating housing stock left to go before hitting a shortage. Not to mention your example of housing in Boston built at the turn of the 20th century. A laissez faire policy that makes the poor wait 120 years for housing is hardly any policy at all.
See this amazing twitter thread with images of historical news paper clippings.
https://twitter.com/enf/status/753435745272995840
Later on, in 1978, most of the city was down-zoned, and in the EIR (Environmental Impact Report) written at the time, it was clearly predicted that this would result in a supply shortage and increased prices. Unless the city made a point to increase density and development in the industrial parts of the city. That didn't really happy to the scale the EIR said was needed.
See: https://twitter.com/enf/status/775185946941591553?s=20
So here we are.