U.S. President Donald Trump's consideration of sending immigrants to so-called sanctuary cities represented by Democrats is more than possible retaliation against his political opponents. It also evokes an event nearly 40 years ago that to this day shapes the partisan debates in the United States and other countries about the impact of immigration.
That debate focuses on whether a large influx of low-skilled immigrants hurts native workers. That answer is complicated and depends upon how studies are framed, according to economists and research conducted around the world. Some economists say low-skilled immigrants from poor countries can hurt low-skilled native workers, while others say such an influx can bolster a local economy.
The Mariel boatlift in 1980 is highly instructive about the impact low-skilled immigrants have on native workers, being the focus of numerous studies. The boatlift was a mass migration of Cubans into the U.S. that began on April 20 of that year and lasted through October, and was allowed by then-President Fidel Castro after a severe downturn in Cuba's economy.
In all, an estimated 125,000 people traveled from Cuba to the U.S. and after reports emerged that some of the migrants had been released from Cuban jails, a heated public debate began in America about the merits of allowing large immigrant populations. A sizable portion of those Cubans, called "Marielitos," permanently settled in the Miami area, says economist Michael Clemens, a senior fellow at the Center for Global Development, a nonprofit think tank based in Washington.
"Everyone assumed at the time the flood (of immigrants) would have to (adversely) influence the labor market," Clemens says. But that didn't happen, Clemens says, who points to research published in 1990 by economist David Card of the University of California-Berkeley as the lasting standard that examines immigration's impact on a local economy.
Card's study found no changes in wage or employment trends between Miami and other similar-sized U.S. cities in his study. Social scientists have since looked at several factors that may explain Card's findings, and a 2017 study by Harvard economist George Borjas challenged the 1990 research by asserting that low-skilled immigrants do damage the employment prospects for native workers.
But the Borjas study is flawed, Clemens says. In a separate 2017 study that Clemens co-authored with Jennifer Hunt, Clemens says Borjas' study ignored female and Hispanic workers and people who had high school diplomas Additionally, Borjas looked only at male workers aged 25-55, and placed an overly representative weight on African-American workers compared to the overall Miami labor market.
However, Borjas forcefully contested Clemens and Hunt by presenting data in 2017 that showed that even removing African-American workers from his analysis did not alter his findings. "In short, using the increase in the relative size of Miami's black workforce after 1980 to dismiss my Mariel evidence performs the job of obfuscating the debate further, but does little to clarify," Borjas wrote.
The flaw in the argument that an influx of workers will adversely affect native workers is in looking at people as if they are bananas, Clemens says. When the supply of bananas increases, the value of each individual banana falls. That isn't the case with humans, Clemens says, whose research shows that as more people arrive in a local economy, demand for goods and services such as housing and food also increases.
Other economists have also stated that overall an influx of migration, regardless of the type, actually boosts the economy, as immigrants can create businesses that hire U.S. workers.
"Immigration brings young workers who help offset the large-scale retirement of baby boomers; immigration brings diverse skill sets that keep our workforce flexible, help companies grow, and increase the productivity of American workers," wrote several Nobel laureates in economics in a previous open letter to President Trump. "Immigrants are far more likely to work in innovative, job-creating fields such as science, technology, engineering, and math that create life-improving products and drive economic growth."
Yet immigration still raises questions about the overall health of the local economy. In other countries, many local residents remain conflicted about the issue, research shows. For instance, a study that began in 1992 in Spain showed that 62 percent of those surveyed believed immigrants from underdeveloped nations caused greater unemployment among local workers, while about 4 in 10 people said local salaries fell because of immigrants. Five years later, the opinions of the same people changed: Only 46 percent of those surveyed said immigrants from underdeveloped countries caused more unemployment, while about 3 in 10 said they negatively affected the local wagers.
During the refugee crisis hitting Europe in 2015, people in Germany were largely uncertain about the economic benefits of accepting large numbers of refugees into the country, with respondents saying it would affect their economy despite studies showing that the new arrivals boosted overall investment.
Low-skilled migration's effect on the local economy has also been an issue in the United Kingdom and one of the main points raised in the Brexit campaign. Yet a 2018 report by the Migration Advisory Committee in the U.K. government, looking at immigrants coming from the European Economic Area, revealed that, "overall there is no evidence that migration has had a negative impact on the training of the U.K.-born workforce, and its effects on local wages was 'generally small.'"
Overall, immigration is a complex issue that should allow pathways for those whose skills are immediately needed in an economy, and those who are exceptionally talented whose fit might not be immediately assessed but can greatly contribute to a nation in the long run, says William Kerr, professor of business administration at Harvard Business School. Immigration policies should also include various strategies for family reunification and well-being, he said. Developing those policies takes time and a tremendous amount of research and sometimes nations fall short.
"There's always going to be some lag between what we think is likely to be optimal, what we learned to be the optimal scenario, and what people are able to craft right now," says Kerr, who is the author of a book on immigration strategies and global talent.
What should policymakers keep in mind when crafting laws to handle immigration? Clemens says it's simple: Countries need to have clear, consistent lawful channels for migration.
"When people have legal status, they make larger financial contributions to society," Clemens says. "It's more beneficial to the country of origin. It's also beneficial to the home country, where people can send remittances. Plus, you're taking money away from smugglers."