I really think it’s mostly lack of supply. If the problem were solely due to lower value of MFH vs SFH we wouldn’t see 1bed market rate condos in SF going for $

I really think it’s mostly lack of supply. If the problem were solely due to lower value of MFH vs SFH we wouldn’t see 1bed market rate condos in SF going for $700k. Of course, all things (including location and sq footage) being equal, it seems logical most people would prefer SFH. No shared walls, nobody living above you, no/less-influential HOA, potentially large upside of land appreciation. However that is a false dichotomy because prices are higher (because land prices are likely to be high anywhere a SFH is near large condos). So what really matters is the demand curve for SFH vs MFH - MFH may be an “inferior good” in the economic sense but it is not so inferior that, for example, rich techies are buying $500k SFH in Richmond, CA rather than $800k condos in SF. The whole narrative of a mass exodus is pretty suspect in general anyway. There is not a huge amount of vacant housing in most cities - the carrying and opportunity costs are too high, though IMO they should be higher. For every person leaving an urban area, on average, someone is replacing them.