Why does a sandwich chain need a non-compete clause?

In the wake of reports that low-wage workers are being subject to non-compete clauses (i.e., terms in their employment agreement that limit the ability to work for other companies in the same field after leaving their current employment), Senators Franken and Murphy introduced a bill last week to protect workers' ability to switch jobs. As the Washington Post reports, the "catchily titled the Mobility and Opportunity for Vulnerable Employees (MOVE) Act ... would ban non-compete agreements for workers making less than $15 an hour, or $31,200 a year, unless the minimum wage in their jurisdiction is higher." Read the whole story here.