It used to be that supply and demand applied to workers and wages within Canada. But globalization has changed that, argues economist Jeff Rubin. When the whole world is your market, there is never a dearth of workers willing to do the same job for less money. On the Agenda, he lays out his arguments for how free trade ruined the middle class, the topic of his new book, “The Expendables: How the Middle Class Got Screwed by Globalization.”