It really depends on the labor market. If they can easily replace one $15/hour employee with another, there's no incentive to raise wages. If unemployment is

It really depends on the labor market. If they can easily replace one $15/hour employee with another, there's no incentive to raise wages. If unemployment is low or they need specific skills that aren't available in their area, they may have to raise wages. Most companies won't do that unless there is some external market force (like labor scarcity) to compel them to do so.