A lot of good points made here.  After all is said and done, renting housing is a business and without adequate pathways to profit, folks will get out of the business, i.e. sell their properties.  Alternatively, as mentioned, deposits might grow to 3 months and rents may increase so that profit can still be made.  Regarding rent control, check out what it did to NYC.  Entire neighborhoods were abandoned by landlords because they could not raise rents enough to cover costs.  Landlords just walked away and let the buildings lapse into disarray.