What happens when millenials don't buy houses?

1) no need to guess...cause we're about to find out!
2) ok, if I have to guess my guess is:  don't worry Rob!  The reasons millenials have given up in the first place is that our parents' generation put this whole country up for sale already.  Don't worry your little head, all the boomers will fuel their retirements by selling of Canada piece by piece to the highest bidder, whoever that may be!  

As long as they get their toys all the way to the grave then they're happy.  And since they hold all the cards, that's all that actually matters.