E-Verify is more cost-effective than Trump's wall in stemming illegal immigration

Immigrants commemorated Mothers' Day on May 10, 2017, in Houston with a protest against SB-4, a bill passed by the Texas Legislature aiming to ban so-called sanctuary cities in the state. The bill is criticized as a "show me your papers" law that would lead to the deportation of non-criminal undocumented immigrants and the separation of families with U.S. citizen children. less Immigrants commemorated Mothers' Day on May 10, 2017, in Houston with a protest against SB-4, a bill passed by the Texas Legislature aiming to ban so-called sanctuary cities in the state. The bill is criticized ... more Photo: Ana Khan-Dorante, Ana Khan-Dorante For The Houston Chronicle Photo: Ana Khan-Dorante, Ana Khan-Dorante For The Houston Chronicle Image 1 of / 1 Caption Close E-Verify is more cost-effective than Trump's wall in stemming illegal immigration 1 / 1 Back to Gallery

The Trump administration's crackdown on illegal immigration has focused on increasing deportations, building a wall on the Mexican border and forcing local law enforcement agencies to turn over undocumented immigrants to federal officials, as my colleague Lomi Kriel examined this week.

Another method, the citizenship authentication system known as E-Verify, is much cheaper and more effective — but it hasn't worked well in all states that now require it, new research shows.

First, some background. For many years, under what was known as the "Texas proviso" for the state's large employers that depend on the immigrant workforce, it wasn't illegal to employ undocumented workers. Congress changed that in 1986, but to little effect.

"All this did was create an industry of fake documents," says Pia Orrenius, an economist at the Dallas Federal Reserve who studies immigration. "And employers, of course, looked the other way. It's a transaction that benefits both parties."

A 1996 law required the creation of a system that allowed employers to quickly and easily check worker-provided documents against federal databases. Over the past decade, eight states have made that system — now known as E-Verify — mandatory for all employers. Now, over half of new hires nationwide are vetted by that system.

Related: The latest U.S. immigration wave is (probably) over

By and large, as Orrenius and research partner Madeline Zavodny found in an earlier paper, the states that required E-Verify saw drops in their undocumented immigrant populations. Word gets around quickly that jobs are only available to citizens, and workers go to other states or return to their home countries. Along with the great recession, those laws probably played a role in the recent decline in the number of people living in the U.S. illegally.

But Orrenius and Zavodny have found that most states haven't enforced their E-Verify mandates very strictly. In Utah and North Carolina, for example, less than 15 percent of employers use the system. Compliance tops out at about 40 percent in Arizona and Alabama. (Texas, and a handful of other states, currently only require E-Verify for government employers.)

So, does compliance with E-Verify mandates have an impact on illegal immigration? Probably. Arizona and Alabama saw substantial decreases in their undocumented populations, compared to how large they would been without the laws, according to Orrenius and Zavodny's model.

But other results are less conclusive. Mississippi and Utah, which had some of the lowest compliance rates, also saw substantial drops in their undocumented populations, while states with high compliance, such as Georgia and South Carolina, saw no change. Orrenius suspects this may be because industries that employ the largest number of unauthorized immigrants, like construction and hospitality, are the ones that ignore the mandate.

Related: Trump's immigration proposals could be a nightmare for Texas

Other effects of E-Verify are worth considering. Orrenius also finds that the poverty rate for undocumented immigrants rose in Arizona after the passage of its mandate in 2006, since many were either locked out of the job market or pushed into underground employment.

Employers often protest E-Verify requirements because they make it difficult to fill workforce demands. Immigrant advocacy groups usually say that any use of E-Verify must be paired with a path to citizenship for those who have been living and working in the United States.

Still, if your goal is to reduce the number of people coming to the United States for jobs, it appears to have more bang for the buck than elaborate border security measures, and perhaps less collateral damage on public safety than turning local police officers into immigration agents.

That is, of course, if you think the U.S. is hurt by having those workers around, which evidence suggests is not true.