It is to the extent that various laws and regulations prevent or strongly disincentivize new construction, yes.
> the fact that it involves most of the western world makes me think it may have to do with monetary policy
It does. Mortgage loans have always been one of the primary places that governments choose to put newly printed money. The ostensible purpose of this is to make it easier for people to own homes, but what it actually does is bid up home prices to the point where consumers are no better off than they were before, but financial institutions and other corporate interests make a nice extra profit. It's similar to the way the easy availability of financial aid for college has not actually made it easier for people to go to the college of their choice (indeed, admission rates to many colleges have sharply declined as financial aid becomes more available), it's just transferred more wealth to the colleges from taxpayers.
It is to the extent that various laws and regulations prevent or strongly disincentivize new construction, yes.
> the fact that it involves most of the western world makes me think it may have to do with monetary policy
It does. Mortgage loans have always been one of the primary places that governments choose to put newly printed money. The ostensible purpose of this is to make it easier for people to own homes, but what it actually does is bid up home prices to the point where consumers are no better off than they were before, but financial institutions and other corporate interests make a nice extra profit. It's similar to the way the easy availability of financial aid for college has not actually made it easier for people to go to the college of their choice (indeed, admission rates to many colleges have sharply declined as financial aid becomes more available), it's just transferred more wealth to the colleges from taxpayers.