Well, once the lease is over people have to sign a new one anyway, so even existing tenants can only lock in rates for so long. And when one landlord ups rent, it’s usually because all the other landlords are doing it too - it seems like they do it in unison, I imagine because they don’t want to have to worry about people leaving for somewhere cheaper. I’m not sure if it’s illegal like price fixing or not, but it doesn’t seem to make a difference in the end.