What Happened to the Supply Side of Housing?

Housing supply is 'inelastic' - unlike spaghetti or toilet roll. Even before the pandemic, rich world was building roughly half as many houses per year as it was in the 19 sixties and 19 seventies. Demand from people was just so high that the building funius couldn't keep up. And so you didn't get that sort of a matching increase in housing supply that would have helped to keep prices in check.