IMO rental prices must go up. With demand for housing staying relatively constant, and the “purchase” market in a downturn, rental markets will see increased demand.
Rents have stayed low for years inspite of rapid appreciation of the underlying property. As more people flow to the rental market it is almost a given that prices will increase. It may be that the easy credit of the last five years has artificially kept the rental market demand down as buyers moved to their new homes instead of rentals.
When the rental market equalizes from the shocks of the easy credit era, we may see the real economic value of housing. If we start with the rentals at equilibrium, and work backward, the underlying economic value is a simple calcualtion based on the cost of money.
If you are in a rental now, it might be a good idea to lock in a lease price or cap on increases before the market does equalize.