Where I lived through 2004-2007, my rent never increased, but that was a much less active rental market than Boston.
Since moving to Boston in 2007 I've only been in the same place long enough to have 2 opportunities for rent-raise requests, and it was raised both times. I don't recall the first (I decided to leave, the company was horrible), and the second the landlord asked for 3% and we haggled it to 2%.
I think some landlords try to balance turnover because there are benefits as well as costs and hassles. Turnover gives you a chance to thoroughly clean and do lots of minor maintenance that a long-term tenant is likely to neglect.
Since moving to Boston in 2007 I've only been in the same place long enough to have 2 opportunities for rent-raise requests, and it was raised both times. I don't recall the first (I decided to leave, the company was horrible), and the second the landlord asked for 3% and we haggled it to 2%.
I think some landlords try to balance turnover because there are benefits as well as costs and hassles. Turnover gives you a chance to thoroughly clean and do lots of minor maintenance that a long-term tenant is likely to neglect.