"Toronto is one of the lowest density cities in the world - we fall way behind Europe in terms of city design, opting for urban sprawl, despite its huge drawbacks for the economy." 

Are we in Europe? Why do have to compare apples with oranges? European countries have much less land compared to Americas or Australia. So their cities are also more congested. But wait a minute. How about Paris? 

*Density of Paris Metropolitan Area - 722/km2 ( Source : Wikipedia)

*Density of Toronto (GTA) -  -   849/km2   (Source : Wikipedia)
And more than 50% of GTA is Greenbelt. So if we exclude the greenbelt area, the GTA has more than double the density of even Paris. No wonder housing is so expensive in Toronto.