Labor union militancy has increased, partly because non-union companies quickly responded to tight hiring conditions, leaving unionized workers behind.

The deal reached by the machinists union, which represents more than 33,000 workers, would cumulatively raise wages by nearly 40 percent over four years, according to details shared by the union.

Boeing and its machinists union have reached a tentative agreement that could end a strike that has halted most production in the past month.