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.

Striking workers at Boeing will vote next week on a new offer that could end a walkout that has lasted more than a month.