The immigrants are coming, and several Republicans vying for the presidential nomination are arguing that the U.S. may be in jeopardy. We should repel immigrants by building walls along the Canadian or Mexican borders, some suggest. If elected, New Jersey governor Chris Christie promises to track immigrants the same way FedEx tracks packages. We must expel those already here through mass deportations, says Donald Trump. “They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people,” Trump said recently about Mexican immigrants.

Who the “good people” are and are not may be a matter of opinion, but actual data might help ease any worries about the economy and waves of crime. “In reality, immigrants do not commit a lot of crime,” says Emily Owens, a University of Pennsylvania professor of criminology and Wharton professor of business economics and public policy. “The immigrant crime rate is very low compared to native people. This idea that immigrants commit a lot of crime — there is no evidence.”

In a brief for Wharton’s Public Policy Initiative, “Trumped Up Charges: Empirical Effects of U.S. Immigration Reform on Crime and Jobs,” Owens and co-authors Matthew Freedman and Sarah Bohn argue that “U.S. immigration policy, in its punitive approach to discouraging immigration, has had little impact on the economic lot of native workers, and has created an environment that actually invites certain types of criminal activity.”

But Trump and other conservatives, it turns out, were merely saying out loud what many have been thinking. In a 2007 Gallup poll, nearly 60% of respondents said that immigration made crime worse. A 2014 Public Religion Research Institute survey found 57% of Republicans saying that immigrants were mostly bad for the economy because they drive down wages, with 33% saying that immigrants help the economy by providing low-cost labor.

But here again, the facts do not square with the notion that immigration is bad for the economy. Experts say that immigration does not bring down wages, and is an enormous driver of economic growth, both in terms of short-term stimulus and job creation and innovation. “The majority of start-ups in Silicon Valley were founded by immigrants in the 1990s, and the greatest economic growth in recent times was driven by immigrants,” says Vivek Wadhwa, a tech entrepreneur and author of The Immigrant Exodus: Why America Is Losing the Global Race to Capture Entrepreneurial Talent (Wharton Digital Press). “It’s all about diversity, it’s all about globalization, it’s all about new ideas. Immigrants have been a part of America’s success in this and every area. Wave after wave coming over have challenged people to think smarter and work harder.”

“The policies we’re putting in place are creating the problem that we say we’re so concerned about.” –Emily Owens

Generally speaking, Wadhwa says, Americans have been supportive of immigration by skilled workers, but the current debate over undocumented immigrants has “polarized the electorate, and now immigration has become toxic. We are in reverse gear right now…. Americans are tolerant, open-minded people — except when they are not.”

Framing the Immigrant

Distrust and loathing of new arrivals has long been an idée fixe in American political discourse. “The theory that immigration is responsible for crime, that the most recent ‘wave of immigration,’ whatever the nationality, is less desirable than the old ones, that all newcomers should be regarded with an attitude of suspicion, is a theory that is almost as old as the colonies planted by Englishmen on the New England coast,” wrote economist and immigrant expert Edith Abbott in the report of the National Commission of Law and Enforcement in 1931.

For all of the heat the immigration question is generating today, the number of immigrants in question is small and getting smaller. Though Mexicans make up the largest group of immigrants in the U.S., between 2007 and 2012, the number living in the U.S. illegally dropped by one million, to 5.9 million, according to the Pew Research Center. With the recession, the net immigration flow from Mexico not only came to a halt, but, in fact, may have even reversed itself.

And yet immigration is very much on the minds of many Americans. A Public Religion Research Institute poll released in February found that 73% of 1,015 Americans surveyed believed that an immigration reform bill should be the highest priority for Republicans in Congress.

Fears have been stoked by sensational crimes — like the July murder of a woman in San Francisco. The alleged gunman is a Mexican national in the U.S. illegally. But statistics show that immigrants commit fewer crimes than others. “A growing research literature about crime and immigration in late 20th century United States is finding, using a variety of data and methods, that immigrants today generally have lower rates of crime than natives,” write Carolyn Moehling and Anne Morrison Piehl in “Immigration and Crime in Early 20th century America” for the National Bureau of Economic Research. Immigrants are also much less likely than natives to be incarcerated, the study says. Data they cite from the U.S. censuses of 1980, 1990 and 2000 on young adult males show that “immigrants have much lower institutionalization rates than the native born — on the order of one-fifth the rate of natives.”

Why would this be? “First, it is about self-selection,” says Owens. “Most of the people coming to the U.S are trying to make a better life, so [they are] people coming over to work. It’s also the case that if you are not a U.S. citizen and you are convicted of a felony, you are going to get deported. So the penalties are much higher; there is a deterrence there.”

Similar data have been found in other countries. In a study called “Clicking on Heaven’s Door: The Effect of Immigrant Legalization on Crime,” Paolo Pinotti of Bocconi University in Milan shows that gaining legal status reduces the probability of an immigrant being reported for committing a serious crime. In Italy, residence permits are awarded on a first-come, first-served basis, with aspirants applying online on specific days called “click days.” By comparing criminal records of applicants before and after click days, Pinotti drew another conclusion: “Illegality imposes a heavy toll on foreign immigrants in terms of poorer employment opportunities, lower incomes and lower access to social services, all of which lower the opportunity cost of engaging in crime, thus increasing the number of crimes committed by immigrants.”

In other words, policies intended to curb crime by making it hard to gain legal immigration status actually can increase crime, which in turn stokes public fear. “The rhetoric leads us to these circular policy positions,” says Owens, “that the rapist is coming over the border. And, one, that’s not true. And, two, the policies we’re putting in place are creating the problem that we say we’re so concerned about.”

“Unskilled immigration in particular is a problem for unskilled domestic workers because of simple supply and demand.” –Peter Cappelli

Owens and her co-authors found an ideal combination of factors to study the relationship between immigration and crime in the U.S.: enactment of the Immigration Reform and Control Act (IRCA) in 1986, and its effect on 29,000 people in Bexar County in Texas (which includes San Antonio, and is about a two-hour drive from the Mexican border) who applied for and received permanent legal status under IRCA. Immigrants who did not seek or receive amnesty faced longer job searches, deteriorated working conditions and saw their wages drop as much as 24%.

And certain crimes jumped. When the IRCA amnesty period expired in 1988 and unauthorized immigrants were cut off from legal employment opportunities, alleged felonies committed by Hispanics rose 59% in the next few years, the study found. “Limiting job opportunities through IRCA increased incidences of crime, but in a very specific way. Empirically, this rise was heavily concentrated in non-violent, felony drug offenses and other income-generating crimes that effectively were substitutes for formal employment — crimes like prostitution, gambling, fraud, forgery, car theft, burglary, robbery and larceny. Income-generating crime charges were actually three times as likely to be filed as non-income-generating crime charges across all Bexar County neighborhoods.”

Owens also points out that the crime rate in the U.S. generally has dropped. “The U.S. population is not that great at intuiting what’s going on with crime,” she says. “People tend to say things are worse, even though crime has been falling pretty consistently for the past decade. America is getting safer and safer, and particularly cities in America are getting safer and safer.”

But will facts like these be able to assuage those who oppose immigration? It will be difficult, says George P. Lakoff, a University of California, Berkeley, cognitive linguist and author of Metaphors We Live By. Immigration, he says, has become one of several boogeymen used by conservatives. “Look everywhere around the country — you have Hispanics coming in and getting jobs. These are the guys who sell you your vegetables and mow your lawn for cheap, but [many people] see these guys succeeding because they start out not making a lot of money and then starting their own businesses because they are smart and they work hard. And there are a lot of people who see them as morally inferior. People don’t think in terms of logic and reason. They think in terms of other principals.”

Lakoff compares resistance to the data to what happened when a DC-10 crashed in Chicago in 1979 — “and then people stopped flying DC-10s when they were one of the safest planes around.”

Immigration as Stimulus

“It is always a challenge when people talk about whether something is good or bad for ‘the economy’ because there are lots of different aspects to it and different winners and losers within the economy,” says Wharton management professor Peter Cappelli, director of Wharton’s Center for Human Resources. “Unskilled immigration in particular is a problem for unskilled domestic workers because of simple supply and demand. It’s also the case that many recent immigrants — legal as well as undocumented — are coming from places with much lower wages than the U.S., so they are much more motivated to work at existing U.S. wages than are equivalent domestic workers. If you are appealing to an audience of lower-skilled voters, they really don’t want to see more immigrants, and they feel the negative consequences on their own opportunities of those who have already come. If you are an employer, on the other hand, you like more immigration for exactly the same reason, because it holds down wages and gives you a more motivated workforce.”

But some more broad-brush looks at the effect of immigration on the economy show it as a plus. “The widespread belief is that illegal aliens cost more in government services than they contribute to the economy. This belief is undeniably false,” writes Francine J. Lipman of the University of Nevada, Las Vegas, in “Taxing Undocumented Immigrants: Separate, Unequal and Without Representation,” published in 2006 in the Harvard Latino Law Review. “Every empirical study of illegals’ economic impact demonstrates the opposite: Undocumenteds actually contribute more to public coffers in taxes than they cost in social services. Moreover, undocumented immigrants contribute to the U.S. economy through their investments and consumption of goods and services; filling of millions of essential worker positions resulting in subsidiary job creation, increased productivity and lower costs of goods and services; and unrequited contributions to Social Security, Medicare and unemployment insurance programs.”

She notes that 85% of eminent economists surveyed have concluded that undocumented immigrants have had a positive (74%) or neutral (11%) impact on the U.S. economy.

Indeed, in areas of the country where immigration crackdowns resulted in immigrants leaving voluntarily or as a result of deportations, wages did not rise compared to those in neighboring counties. Citing an unpublished study by Sarah Bohn and Rob Santillano, Owens and her colleagues write: “The implication here is that native and foreign-born workers are likely complements, not competitors, because each group fills specialized needs in respective industries.” Decreases in foreign-born Mexican immigrants “did nothing to improve the employment opportunities for low-skilled native residents.”

“Competition is OK when you are benefiting from it, but when you have to work harder you don’t want competition.” –Vivek Wadhwa

In making the case for executive orders that would ease some aspects of immigration policy, President Obama promises great economic benefit: at least a $90 billion increase over a decade in the gross domestic product and a $25 billion reduction in the Federal deficit, according to the White House Council of Economic Advisors. But conservatives in Congress are working hard to block these executive orders.

Feeding the Talent Pipeline

In nearly every sector — arts, science, technology, business — immigrants in the U.S. have proved efficacious to innovation. Nearly 40% of students at the Curtis Institute of Music, which is tuition-free and has the lowest acceptance rate of any U.S. music conservatory, come from abroad (Lang Lang is but one success story). In 2011, 70% of finalists in the Intel Science Talent Search were immigrants or children of immigrants.

More than 40% of companies in the Fortune 500 were started by immigrants or children of immigrants. These businesses employ more than 10 million people worldwide and generate annual revenue of $4.2 trillion, according to the Partnership for a New American Economy, a coalition of U.S. mayors and business leaders advocating for immigration reform. In 2011, 28% of all new businesses in the U.S. were started by immigrants.

And yet the government remains stuck in neutral on immigration reform. More and better research is needed to steer public policy, note Owens and her colleagues. “While it is not clear that policies like heightened policing or employer sanctions are effective at all in reducing immigration, it is also unknown how much loosening those restrictions would increase immigration,” they write. “The less responsive immigration flows are to U.S. policy, the more policymakers should consider trying to reduce the negative social effects associated with undocumented immigrants directly, rather than waging a seemingly futile battle to reduce the number of people overstaying their visas or entering the country illegally.”

“The fact is, we have more than a million skilled immigrants now in limbo,” says Wadhwa. “We keep bringing people in on temporary visas, but not increasing the number of green cards, which is why we have a reverse brain drain of skilled talent leaving the country. It’s the green cards we need to focus on. We don’t want unlimited immigration, but if companies want to employ people, let them employ people. No politician is talking about this.

“Competition is okay when you are benefiting from it, but when you have to work harder you don’t want competition,” Wadhwa continues. “People want their jobs protected. You have these stories about people training their replacements, and yes, [immigrants] do take some jobs, there is no doubt about that…. But that is competition. That is the American way.”