President Obama on March 13 signed an order directing the Labor Department to expand the class of employees entitled to overtime pay. Currently, if a salaried employee makes more than $24,000 a year and is part of management—if he manages the business, directs the work of other employees, and has the authority to hire and fire—that employee is exempt from overtime coverage. The president wants to raise this salary threshold, perhaps as high as $50,000, demoting entry-level managers to glorified crew members by replacing their incentive to get results with an incentive to log more hours.

At...