Many high-tech companies in the United States look overseas to fill talent gaps in their employment ranks by hiring skilled immigrants, often sponsoring the visas these workers need to live in this country. Critics say this can create an unpleasant fallout effect,the pushing out of older workers with higher salaries.

But new research indicates that although many tech firms do tend to favor employing younger workers, older native workers are not losing their jobs in droves directly as a result of the immigrants who are coming in.

“We don’t find rampant evidence of this idea that when a new immigrant comes in, the older worker is shown to the door,” said Harvard Business School Associate Professor William R. Kerr, who recently cowrote a working paper called Skilled Immigration and the Employment Structures of US Firms with Sari Pekkala Kerr of Wellesley College and William F. Lincoln of Johns Hopkins University.

In the United States, the immigration of skilled workers is particularly prevalent among firms in the technology fields.

In 2008, immigrants represented 16 percent of the US workforce with a bachelor’s education, and they accounted for 29 percent of the growth in this workforce during the period between 1995 and 2008. In jobs closely linked to innovation and technology, the share of immigrants was even higher, closer to 24 percent.

“Skilled immigration is important for the United States, where we do have a large Baby Boomer generation approaching retirement and leaving the workforce,” Kerr says. “Some European countries also have workforces that have been aging substantially, and the replacement rate in the population for some of these countries is even negative; not enough new people are being born to replace people in their later years. Countries around the world are looking at immigration as one of the ways to keep the population base at its size or greater, and even better if that can be a skilled workforce.”

Bitter Debate

Yet in the United States, specific policies and admission levels of skilled immigrants remain a topic of bitter debate.

Some who advocate for higher rates of skilled immigration have recently used the phrase “national suicide” to describe the limited admissions of skilled workers compared to low-skilled workers in the United States. But critics are opposed to expanding admissions, saying skilled immigration rates are already too high.

Most previous research focused on studying immigration through shifts in the supply of workers to a particular labor market. But Kerr and his fellow researchers took a rare route by looking at skilled immigration through the lens of the US firm by studying how the hiring of these immigrants affected the employment structures within 319 large employer firms and top patenting firms during the period between 1995 and 2008.

Many firms bring in immigrants through the firm-sponsored H-1B visa, the largest program for temporary skilled immigration to the United States. A company identifies a worker it wants to hire and then applies to the US government to obtain the visa.

Young workers account for a large portion of skilled immigrants, with 90 percent of H-1B workers under the age of 40. The visa is used especially for occupations in science, technology, engineering and math, which account for about 60 percent of successful applications. About 40 percent of H-1B recipients between 2000 and 2005 came from India, while 10 percent came from China.

Once the worker has migrated, the immigrant is essentially locked in with the firm until the person can obtain permanent residency or another visa. In many cases, the firm ends up sponsoring the immigrant for permanent residency, which strengthens the worker’s ties with the firm even more.

Opponents of skilled immigration argue that companies are saving money by underpaying their immigrant workers substantially. Although Kerr agrees that many immigrants are underpaid when compared to native workers, he notes that many studies find the average difference in pay is only about 3 to 5 percent, and others find no differences or positive effects. This may be because the laws that surround skilled visas don’t allow companies to pay much less than the prevailing wage.

“The most extreme studies find a differential of 20 percent or thereabouts, but even that difference is not as substantial as it first sounds,” he says. “There are legal fees and recruiting costs for hiring immigrants, and that kind of stuff will quickly wipe out any underpayment that a firm would get off a $50,000 salary. So I don’t have the belief that firms are using this to reduce the wage level that they have to pay their young workers in these companies.”

Kerr points to other factors beyond salary: “Younger immigrant workers are often more tied to the firm, are willing to work long hours, and often have fewer family commitments. Their salary may also be lower, especially relative to older workers whose salary has increased over time, but that can be second-order to these other traits.”