I'm no expert, but I do know that in Indianapolis we've had many housing developments in the downtown area that have a requirement for a certain percentage of u

I'm no expert, but I do know that in Indianapolis we've had many housing developments in the downtown area that have a requirement for a certain percentage of units to be rented below market rate. You have to apply to rent those units, and you must meet the income requirements, in that you can't make above a certain threshold if income. (Not sure what other factors are taken into consideration.) To me, this seems like somewhat of middle ground between being 100% market-driven vs. full-on rent control.