It's no secret that the financial divide between CEOs and average worker in the U.S. has been growing. But in one case, the pay gap between corporate chiefs and employees has reached almost 6,000-to-1: Weight Watchers, where CEO Mindy Grossman earned 5,908 times what the median worker took home last year.

An ideologically divided Supreme Court ruled Monday that companies may require workers to settle employment disputes through individual arbitration rather than joining to press their complaints, a decision affecting as many as 25 million workers.

The court's conservative majority said that the 5-to-4 ruling was a logical reading of federal law, and Congress' preference for using arbitration to avoid costly and time-consuming litigation.

It only takes a moment talking to Emily Galvin, an apprentice with Ironworkers Local 7 in Boston, to grasp how her first year learning the skilled trades has transformed her life. For one, she has a fresh understanding of the anatomy of a city—of roads, bridges and buildings. She’s taking classes in structural steel, tension, rebar and labor history. “I love how we use mats of rebar,” Ms. Galvin says, “to make reinforced concrete for floors or knee-walls, like for a parking garage.”