In reply to Andrew.

Yes. If the City could ensure all infraction tickets were paid, that would eliminate the bad debt, resulting in a net profit for this division.
It would be close (the revenue from the collection agency would be the city's "cut" from the bad debt that was sold to a collection agency), so you'd have to also take that revenue stream out... a net profit of $32,864 (in the case of 2011).
Of course, you run into other issues. Like how much would your proposed "more effective system" cost to implement and run?
I'm curious as to what transpired that resulted in the annual "bad debt" line item grow in 2010 to more than double the 2007 number -- especially when the revenue was less than 2/3rds. Did the City change their accounting procedure and start writing debt off sooner? Or did people just start deciding that they'd let the City try and catch up with them, because the tickets had gotten outrageously expensive?
Interestingly, the removal of meters hasn't necessarily solved the parking problem -- it just changed it. You now have office workers in some areas (e.g. 2nd/3rd & Victoria) that collude to evade the system. They'll all park in the "maximum 2 hour" slots, and every 110 minutes go do a unified synchronised driving excursion to change blocks (but just trade spots).
So there's no additional patron parking for businesses (actually, it's reduced) and the City's parking-lot revenue is down because these people no longer need the spot in the City-run lot.
I'd suggest the City needs to come up with some better ways of enforcement. Maybe The Boot would help -- have an outstanding ticket from more than a week ago? Come back to a yellow piece of metal on your front tire... costs double the ticket price to have it removed.
*shrug* It's a bigger issue than I think the current council (especially with its current leader) is up to tackling.