Cleveland fans who'd assumed that LeBron James would remain unfailingly devoted to the Cavaliers are mortified that he's packing his bags for Miami. But his move simply puts him in step with others of his generation.

If younger workers have displayed anything as employees, it's that they prize mobility more than they do fidelity to their employers.

"Stability and company loyalty are high values for . . . those whose worldviews were shaped by experiencing the Great Depression in their formative years," Chip Espinoza, Mick Ukleja and Craig Rusch write in their new book, "Managing the Millennials." "But the work world has changed."

Much of this attitude is being driven, of course, by the behavior of those doing the hiring. Rock-solid pensions, generous health benefits and job security — all staples of the social contract between employer and employee from the mid-1940s through the late 1970s — have evaporated as companies have braced for global competition and as a pernicious shareholder-is-all mentality has taken root.

An analysis by Princeton economist Henry Farber shows that the percentage of private-sector male workers who've been with the same employer for at least 10 years fell from 50 percent in 1973 to just 35 percent in 2006, and the proportion of those with 20-year tenures dropped from 35 percent to 20 percent over the period.

But the erosion in loyalty is not merely a function of corporations being greedy or girding for the rough-and-tumble of today's marketplace. On the flip side, numerous studies have concluded that younger people, in particular, don't have as much allegiance to their employers as do baby boomers or even Gen X'ers.

One survey, released in 2004 by Harris Interactive, found that only 47 percent of those 18 to 34 years old "really care about the fate" of the enterprise for which they work. That compares with 64 percent of those 55 and older.

In any case, these younger workers don't imagine they'll stick around very long. In his book, "The Trophy Kids Grow Up: How the Millennial Generation Is Shaking Up the Workplace," Ron Alsop cites a study in which two-thirds of 18- to 28-year-olds said they plan to "surf" from one job to the next. And 44 percent, he reports, go so far as to say that they'd renege after having accepted a job if a better offer came along.

To be sure, the recession and a stubbornly high unemployment rate have dampened the ability of many young people to be so desultory. But at some point, the downturn will pass, and evidence suggests that Gen Y workers — especially those who are college educated — remain eager to job-hop when they can.

"Just because we're experiencing an economic meltdown for the first time does not mean that we're going to hide in the corner," Rebecca Thorman, who gives career advice to fellow Gen Yers, declared on her blog, Modite, earlier this year. "We're not going to settle."

Thorman went on to encourage young workers to "get paid what you're worth," explaining that the best way to realize a salary boost is to leave one employer for another.

Numerous studies have concluded that younger people, in particular, don't have as much allegiance to their employers as do baby boomers or even Gen X'ers.

You can't expect to see your income rise sharply "by staying at the same job unless you're there for a very long time," Thorman asserted. "You just can't."

For employers, there are few issues that are as difficult as coping with this mind-set. In their frustration, many gripe about their younger workers, labeling them entitled, arrogant and egocentric. But it's not quite that simple. This same age group, after all, is also team-oriented, technologically savvy and committed to tackling some of the world's most pressing problems.

There are many positives to tap into for those employers willing to learn and to try.

Indeed, companies have a shot at attracting and retaining top talent if they exhibit a strong, and genuine, sense of social responsibility, challenge employees by offering them opportunities to take on new roles, give workers a chance to find fulfillment by sending them abroad, are sensitive to people's work-life balance and provide excellent training and development programs (something sought by millennials even more than cash bonuses, according to PricewaterhouseCoopers).

Still, even the best employers shouldn't count on much fealty in the end.

The trend is inescapable: More and more, the labor force will find itself chock-full of free agents, unabashedly looking for a better deal.

Rick Wartzman is executive director of the Drucker Institute at Claremont Graduate University. He wrote this for the Los Angeles Times.