Here is some research sure to rankle every employee who has applied for an internal promotion and been passed over in favor of someone brought in from the outside.

According to Wharton management professor Matthew Bidwell, “external hires” get significantly lower performance evaluations for their first two years on the job than do internal workers who are promoted into similar jobs. They also have higher exit rates, and they are paid “substantially more.”

About 18 percent to 20 percent more. On the plus side for these external hires, if they stay beyond two years, they get promoted faster than do those who are promoted internally.

“Most jobs are entered into through a variety of different routes, sometimes by being hired from the outside and sometimes by moving up from inside the firm,” says Bidwell. “I was curious as to what the effect of these different routes would be” on an individual’s job performance. His research is presented in a paper titled, “Paying More to Get Less: The Effects of External Hiring versus Internal Mobility.”

The issue has significance for organizations, Bidwell says, as they think about where they source their employees, especially higher-level ones. Do they “grow their own” or do they go out into the job market and hire outsiders? “My research documents some quite substantial costs to external hires and some substantial benefits to internal mobility,” he notes.

Getting up to Speed

The context for Bidwell’s research lies in the increased mobility of workers over the past three decades as companies have turned away from offering lifetime employment in favor of relying on the external labor market to find experienced workers at all levels of the organization.

By comparing internal mobility and external hiring processes—looking specifically at performance and pay—Bidwell’s research can help employees learn more about “the consequences of their career decisions,” including the tradeoffs that characterize internal and external mobility, Bidwell writes in his paper.

Some of those tradeoffs are easily identified. In noting that external hires need about two years “to get up to speed” in their new jobs, Bidwell suggests it is because outsiders need that amount of time to learn how to be effective in their new organization—specifically, how to build relationships. Meanwhile, the risk of failure is substantial. Although external hires are paid quite a bit more than employees promoted into similar jobs, “this is not a free lunch for the external hires,” he says. “There is a much greater risk of being let go during those first few years, mainly because they may not develop the necessary skills and thus will not perform as well as expected. Then, too, they might decide to leave voluntarily.”

While doing his research, Bidwell noted one particular difference between the external hires and those already in the company who are being promoted. “People hired into the job from the outside often have more education and experience [than internal candidates], which is probably some of the reason they are being paid more,” he says. “When you know less about the person you are hiring, you tend to be more rigorous about the things you can see”—such as education and experience levels listed on a person’s CV, or what Bidwell calls “externally observable attributes.” And yet “education and experience are reasonably weak signals of how good somebody will be on the job,” he notes.

Those tradeoffs might help explain why external hires earn so much more than internal employees promoted into the same jobs. If these hires have better resumes and are perceived as able to get a job more easily outside the company, then they can demand higher pay than internal people. Hires may also want higher pay to reflect the unfamiliar environment that they face on coming into a new position. Hiring managers confirm that they typically pay 10 percent or 20 percent more to pull people out of positions “where they already have some security and where people know them and know they are doing a good job,” Bidwell says.

He acknowledges that his research may frustrate an organization’s in-house workforce. “It is sadly the case that being more marketable, as external candidates are, is always going to be valuable and will generally lead to higher compensation. So the question is, should internal people threaten to quit to raise their pay?” It’s well known in academia, for example, that the only way to get a significant pay raise is to nail down an outside offer, Bidwell notes. “But in some organizations, that’s an easy way to get fired. People will take it as a signal that you are disloyal.”

Bidwell offers this career advice: “If you like where you are, stay there. Or at least understand how hard it can be to take your skills with you. You think you can go to another job and perform well, but it takes a long time to build up to the same effectiveness that you had in your previous organization. You need to be aware that often your skills are much less portable than you think they are.” Bidwell is clearly a fan of internal mobility. “While the pay may be less, your performance is better, and there is more security.”

Art: Nigel Buchanan

“Let’s Make a Deal”

For his research, Bidwell analyzed personnel data from a U.S. investment banking division from 2003 to 2009. In that study, he documented twice as many internal promotions as external hires. Investment banking, Bidwell writes, represents “an interesting context in which to study the effects of internal versus external mobility [because] organizational performance often depends on the skills of the workforce, [thereby] increasing the importance of personnel decisions.” In addition, workers in banking are “notoriously mobile, making this a context in which organizations regularly engage in external hiring at all levels.”

One important feature of investment banking jobs is that promotions tend to involve some measure of continuity with the prior job. Promotions often involve getting a higher title, such as vice president or director, while continuing to do similar work. In fact, as Bidwell notes, promotions in many organizations do not instantly lead into a very different job. Instead, responsibilities increase gradually, being recognized over time by a promotion. When considering their future staffing needs, though, organizations still must think about how they will acquire the workers capable of operating at the higher levels: Will it be by hiring or promotion?

Bidwell found similar patterns for different kinds of jobs and within different organizations. He analyzed separately the investment professionals (traders, salespeople, research analysts and investment bankers) and the support staff at the research site. His findings about pay and performance were consistent across those groups. He also looked at another investment bank and a publishing company, and found the same results of “paying more for external hires while giving them lower performance ratings.”

He concludes, however, that the nature of the promotion mattered. Unlike other promoted workers, those who were simultaneously promoted and transferred to another group did not perform any better than external hires. Bidwell speculates that “the skills that are important to our jobs may be very specific to the positions that we are in. Even large changes in the nature of jobs within the organization were associated with performance declines.”

Yet overall, Bidwell says, external hiring has grown much more frequent since the early 1980s, especially for experienced high-level positions and especially in larger organizations. “It used to be that smaller organizations always did a lot of outside hiring while big ones focused more on internal mobility. But now the pendulum has shifted toward external hiring and away from internal mobility for large organizations as well.

“Companies should understand that it can often be harder than it seems to bring in people who look good on paper,” says Bidwell. “In addition, there is a suspicion that ‘the grass is always greener’ attitude plays a role in some companies’ desire to hire from the outside. Managers see a great CV and get excited about playing “Let’s Make a Deal,” even when it’s hard to know what weaknesses the external hires bring with them.”

On the other hand, “to promote more people internally also means that companies need to have a long-term perspective and know how big a pipeline of people will be needed in the future,” notes Bidwell. It also requires managers to ensure that internal people are aware of the opportunities open to them. “Finally, there are clearly some costs to internal mobility—for example, the cost of training people in-house versus piggybacking on someone else’s training.”

Another variable in the mobility equation, he adds, concerns noncompete clauses which tend to complicate the movement of employees between competing firms. “Although these have not always been so salient in investment banking, noncompete agreements have become increasingly important in many states and many jobs, particularly in areas like technology where employers can plausibly claim that employees will take critical competitive knowledge with them.”

“Involuntary Exits”

In his paper, Bidwell argues that the differences between internal and external mobility all ultimately stem from two factors: the skills workers bring from their prior jobs, and the amount of information that firms and workers have about each other.

He comments on the significant amount of new knowledge that external hires are required to learn, even in those jobs that demand “high levels of general skills, such as securities research, scientific research and surgery. … Although such work depends on individual workers’ skills and knowledge, it can also require intense coordination with others in the organization.” Because internal movers have longer experience within the firm, “they are likely to have already acquired important firm-specific skills that new hires will lack,” Bidwell writes.

In terms of the process that takes place when firms and external employees are eyeing each other for a possible matchup, Bidwell writes that the task can be difficult because each side often has “highly incomplete information about each other. Firms struggle to evaluate the true qualities of applications, and workers struggle to know which of the jobs available will best suit their preferences and abilities.” But, as Bidwell notes, companies obviously have more information about internal job candidates, including how well they have performed in prior roles and how well they fit in with the current organization.

Bidwell suggests that his paper “provides unique evidence on the value to firms of internal labor market structures. Results show that internal mobility allows the firm to staff higher-level jobs with workers who have better performance but are paid less.” By detailing the strong advantage of internal mobility over external hires, he adds, “these findings help to explain the continued resilience of internal labor markets in the face of pressures for worker mobility.”