[smiler]

If interest rates go up and the person who you're renting off has a mortgage on the place and his interest rates go up - your rent will go up.

[yummyfajitas]

Then you move out and rent from someone who isn't charging above-market rates.

"Mark to mortgage" == vacancy. If you want to successfully speculate on real estate (as any homeowner does, landlord or occupant), you need to be willing to take losses over long periods of time.