by Peter Cappelli  |   8:00 AM November 5, 2014

Older workers — those who are at or approaching the traditional retirement age of 65 ­— are the fastest-growing segment of the workforce and one of the fastest-growing groups in the overall population. In the U.S. the number of individuals aged 65 or older will increase by about 66% between now and 2035. The growth is driven in part by the Baby Boomer generation, but even more so by an increased life expectancy that’s creating more healthy years for more people.

As we learned in our research for our book, Managing the Older Worker, people who are 65 today have about the same risk of mortality or serious illness as those who were in their mid-50’s a generation ago. The percentage of the population over age 65 who are at serious risk of mortality or life-threatening illness will grow by only about 16% between now and 2035, which means that there will be a huge cohort of healthy individuals in that age group who want and need to work. These changing demographics will transform the U.S. labor market and society as a whole. Any employer who wants to engage a skilled, motivated, and disciplined workforce cannot afford to ignore them.

And yet, these workers are being ignored to some extent. About three quarters of individuals approaching retirement have for some time said that they would like to keep working in some capacity, yet only about a quarter of them actually do. Something is keeping them from working, and that something is on the employer side.

Engaging the older workforce should not be such a big challenge. Older workers tend to be in the workforce because they want to be — relatively few look for jobs because they need them to survive. (During the Great Recession we heard a lot about people not being able to retire because of finances, but we’re hearing that less now.) Older workers want to keep working first and foremost because it keeps them engaged with other people, and also to feel as though they’re contributing. Money is further down the list. Older workers also know what they are getting into and what is required when they accept a job — much more so than younger workers.

So, why aren’t we seeing more older employees in the workforce? The problem seems to be getting them in the door in the first place. Discrimination is certainly one reason. Evidence suggests that we are more biased in our views of older individuals than we are of minorities and women. It’s easy to see that bias if we compare the images that come to mind when we contrast the words “older,” which brings up negative stereotypes, and “experienced,” which brings up positive ones.

The other challenge is fear. Younger supervisors are often afraid of managing older employees because these older workers have more experience than they do. The less experienced managers may wonder, “How can I say, ‘Do this because I know best’ when often I don’t know best?” Older workers may also have some initial trouble being managed by younger supervisors, especially those with less practical experience than they have. But it’s up to supervisors to shape the relationship beginning with the first interaction by saying how they want to use the older worker’s experience, while pointing out what their own responsibilities are for setting goals and holding people accountable.

It’s not just a confidence issue. Younger supervisors may find that what works with most of their staff doesn’t work for older employees. They aren’t as fearful of being fired (they’re already at retirement age) and they have less interest in promotions or a big payout in the future.

So how do you keep an older worker engaged? Start by acknowledging and using their experience. Certainly this is true for any age group: Everyone wants their expertise to be recognized, especially by the boss. But with older workers, it’s even more important, because they typically have a lot of experience — so ignoring it is especially irritating. And older workers themselves can be prickly about being managed by someone who knows less than they do.

The military has developed some good tactics for recognizing and appreciating older workers’ expertise based on the efforts of generations of junior officers fresh out of college and struggling to manage older, more experienced sergeants. Military leaders now advise those officers to treat their experienced subordinates as partners, at least behind the scenes.  The supervisor is still in charge, but he’s missing an opportunity (and is more likely to make a mistake) if he doesn’t check in with his more experienced subordinates — at least to hear their thoughts — before making important decisions. The supervisor still sets the goals and holds people accountable for meeting them. But the subordinates have a big say in the execution, and when they walk out of their private meetings with their managers, they need to be on the same page.

In the workplace, it’s useful to check in with individual older workers to ask them what problems they could foresee in executing a specific task (“Here’s what we need done”). If you don’t take any advice they offer, it’s helpful to explain why not (“I know it’s an aggressive deadline, but it’s important to finish this before the new manager takes over”).

In terms of their interests, older workers tend to be more like young workers than like their middle-aged peers. Their big financial needs are typically behind them, work is often a source of social interaction for them, and they care more about the good works that their employer might be doing than the cohorts in middle age. Supervisors should consider giving older works jobs with more customer interaction (frontline jobs) or those dealing with internal customers.

Research also suggests that putting older and young workers together helps both groups perform better. They make good allies in part because of their similar interests, but because of their different stages of life, they are less competitive with each other than workers in the same age cohort might be. That means that they are more likely to help each other and to form good teams.

The bottom line is that companies looking to increase engagement, performance, and loyalty need to do a much better job of engaging this growing — and valuable — segment of the workforce. For employers who say they want a workforce that can “hit the ground running,” that doesn’t need training or ramp-up time to figure out what to do, that will be conscientious, and that knows how to get along with others, older workers are the perfect match.