The cost of housing - renting or buying it - seems to go in only one direction lately, and that's up. And while that's making it tough for many to keep a roof over their heads, it's providing tidy returns to investors, according to ,Push,, a documentary premiering tonight on TVO that makes the connection between profits and the affordability crisis. To delve into the details we welcome economist Benjamin Tal, realtor Shaun Hildebrand, urban and land development researcher Diana Petramala, and University of Waterloo planning professor Martine August.