After breakfast, his parents left for their jobs, and Scott Nicholson, alone in the house in this comfortable suburb west of Boston, went to his laptop in the living room. He had placed it on a small table that his mother had used for a vase of flowers until her unemployed son found himself reluctantly stuck at home....

Complicating the generational divide, Scott’s grandfather, William S. Nicholson, a World War II veteran and a retired stock broker, has watched what he described as America’s once mighty economic engine losing its pre-eminence in a global economy. The grandfather has encouraged his unemployed grandson to go abroad — to “Go West,” so to speak.

“I view what is happening to Scott with dismay,” said the grandfather, who has concluded, in part from reading The Economist, that Europe has surpassed America in offering opportunity for an ambitious young man. “We hate to think that Scott will have to leave,” the grandfather said, “but he will.”

The grandfather’s injunction startled the grandson. But as the weeks pass, Scott Nicholson, handsome as a Marine officer in a recruiting poster, has gradually realized that his career will not roll out in the Greater Boston area — or anywhere in America — with the easy inevitability that his father and grandfather recall, and that Scott thought would be his lot, too, when he finished college in 2008.

“I don’t think I fully understood the severity of the situation I had graduated into,” he said, speaking in effect for an age group — the so-called millennials, 18 to 29 — whose unemployment rate of nearly 14 percent approaches the levels of that group in the Great Depression. And then he veered into the optimism that, polls show, is persistently, perhaps perversely, characteristic of millennials today. “I am absolutely certain that my job hunt will eventually pay off,” he said....