The big thing is that they all use a piece of software to create a cartel. The rent prices in the US are being artificially inflated by companies like Zillow that chart all the “comps” in an area. A “comp” is a completed sale. The thing is that they can buy a property at 120-300% of actual value in the area to create a “comp” that artificially inflates the “value” of all the other properties in the area, thereby allowing their property management division to jack up rents, which since they all share what they are charging jacks up all the other rents in the area.