ATR's are on around 49% burn of Q400's for very similar load. The evidence will be borne out over time, what evidence do you need.. just look at the specs of both aircraft.
Is the cost base of the incumbent crews and their industrial practices not a drain on the airline as well?
No that is why I mentioned the gravy train, the incumbent awards are complicated and expensive, lets face it the long haul award is dying a slow death, but I still suspect the vast majority of waste is in the admin side.