With a TTC fare hike likely and possible route cuts on the way, I was intrigued to discover an article on the viability of a fare-free public transit system.
The article discusses the relationship between fare hikes and ridership (fare up = ridership down) and cites Toronto as an example:
Just one example is Toronto's transit system, which went into a 12-year downward spiral throughout the 1990s after a series of fare increases and resultant service cutbacks. The authoritative Transit Cooperative Research Program in Washington, D.C., has clearly documented how fare increases always result in lower ridership.