I think we have a lack of evidence. There are anecdotes from other countries, but I raised some reasons why those other countries are not great comparators for where Canada is right now. There are some meta studies that have come out and said that there appears to be no difference between RBT and SBT. Those suffer from the flaw, which is noted in Professor Solomon's work, that there are no studies designed to compare these two regimes. That is the problem and that's the rational connection difficulty.
On September 29th, 2016. See this statement in context.