Oh, and about the MBM...
Re. "...the Market Basket Measure (that) provincial welfare departments use to set social assistance rates."
No Canadian province or territory uses the Market Basket Measure (MBM) to set its welfare rates. The MBM was originally designed as a benchmarking tool to help in measuring the success of the National Child Benefit initiative in the late 1990s, but no Canadian jurisdiction has ever used it to set welfare rates. Welfare rates are set by political decision except in a few provinces (QC & NL spring to mind) where the rate of annual increase is set in the welfare regulations.
[The notion of welfare rates being "set" is a bit of a misnomer --- in all jurisdictions, the welfare rates were "set" a long time ago, and since then it's been a political decision as to if/when the rates are increased and by how much...]
For welfare rate information for all jurisdictions, see:
http://www.canadiansocialresearch.net/welfare.htm

"...will we still define one-half the median as “low income” when the median is a million dollars?"
This is the classic, simplistic argument of social conservatives against a relative poverty line.
Once and for all:
YES, Mr. Coyne, we *will* still define one-half the median as “low income” when the median is a million dollars, because at that theoretical point in time, the cost of everything will have also risen astronomically compared to today's prices.
For links to information about poverty measurement in Canada, see:
http://www.canadiansocialresearch.net/poverty.htm