When an employer sponsors a foreign worker for a visa, the Department of Labor checks that hiring the worker won’t undercut wages or working conditions for U.S. workers in the same role.
The DOL sets a prevailing wage for the position based on statutory rates, collective bargaining agreements, or government wage survey data for that occupation and location. The sponsoring employer must offer at least that wage. Working conditions are reviewed too, though wage disputes are far more common than working-condition disputes. Only if the DOL is satisfied that the hire won’t adversely affect U.S. workers will the labor certification be approved.