[Hali87]

IIRC that list basically measures how integrated a city is into the global economic sphere. The higher up the list, generally the more diversified the economy and the more that decisions made in that city tend to "affect things" from a business perspective. The "sufficiency" cities are less influential in terms of decisions made, but are important cogs in the trade/manufacturing networks and are regional hubs for business and trade.

I'm not sure exactly what numbers these would be based on but I don't think there's much to read into the fact that Saskatoon is listed and Regina is not, for example.