There are two warriors in the conversation in Quebec. One is a demographer named Castonguay, and the other is Jack Jedwab. Every time these numbers come out, there's a big fight in the press.
Median income is the income at which 50% of the incomes are above and 50% of the incomes are below. It is a much better indicator of what the average person makes than the mean.
The mean takes the lowest and the highest incomes, subtracts it and divides it by two. So if you have a great deal of economic disparity, a lot of very rich people, it will bring up the mean income and it will give you a false picture. It will make the people in the community look like they have a higher income than they actually do.
So a median is a much more accurate way, from a social science and policy perspective, to measure income in a given cohort.