A New York Times article helpfully enumerates the possible responses a fast-food franchise operator might take to the New York State dictating a $15 minimum wage for fast-food workers who work for a chain with at least 30 locations. "A wage increase applying to such a narrow segment of the economy is bound to have unintended consequences," the Times reporter says:
A business owner who previously ran chain fast-food franchises might choose instead to open independent stores to avoid the wage requirement. An owner who already has 29 stores might choose not to expand. If subject to the requirement, an owner could install iPads at the counters to take orders instead of live, wage-earning humans. An owner could buy food that is already prepared by an outside vendor (who wouldn't have to pay the higher wage) and employ fewer workers in the kitchen.
The article concludes by quoting a Harvard professor suggesting an alternative — a higher minimum wage for everyone, not just employees of chain fast-food restaurants. But the iPad consequence could still apply, as could the "outside vendor" consequence, so long as the "outside vendor" is outside the jurisdiction where the minimum wage increase applies.