> Engbom and his colleagues offer two main arguments for why American workers are less likely than they used to be 40 years ago to receive competitive offers. The first is “increased employer concentration,” he told me, which reduces the scope of job shopping for workers.

> The other reason Engbom and his co-authors offer for the broken job ladder is the rise of noncompete agreements that prevent employees from working for a competitor, often in a defined geographic region and for a specific amount of time.