These two maps, taken in conjunction, do not provide a good argument for housing deregulation. Even if we accept that the maps correlate quite well (and ignore whether there is any causal link), there is an assumption that the author is not stating plainly: that housing deregulation leads to young people being able to move out of their parent’s basement.

Look at the Scandinavian, very deep green countries at the top of the map. They all have strictly regulated construction processes, with political involvement in city planning. It takes many long years of project planning before you can put a spade in the ground in Stockholm. What’s more, there is government meddling in rent setting - they are not free markets. Still, they seem to do OK?

I don’t know what the author has against housing regulations but this argument is missing some part.