At least for San Francisco, the seeds of the current shortage started as early as 1912 with the establishment of the planning commission. See this amazing twit

At least for San Francisco, the seeds of the current shortage started as early as 1912 with the establishment of the planning commission. See this amazing twitter thread with images of historical news paper clippings. https://twitter.com/enf/status/753435745272995840 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 https://twitter.com/enf/status/775185946941591553?s=20 So here we are.