President Trump made waves last week by saying that he didn’t want to mandate E‑Verify because the system—which intends to stop illegal workers by checking their information against government databases—is too “tough.” He claimed that when he built the Trump Hotel in D.C., the system rejected nearly 30 people for each person it accepted. But Trump is wrong: E‑Verify catches fewer than one in six illegal workers. It’s been more than a decade since E‑Verify reliably stopped illegal hires.

Methodology

E‑Verify relies on government records to try to identify U.S. citizens and legal workers applying for jobs. If the system worked, it should deny applicants roughly in proportion to the illegal share of the labor force. From Census surveys, demographers at the Pew Research Center have estimated that about 8 million workers—or 5 percent of the workforce—lacks authorization to work.

But because so many illegal immigrants work in seasonal industries and are more likely to change jobs, they are overrepresented in new hires who are run through the system. In addition, the specific companies that use E‑Verify are more likely to be in industries with an overrepresentation of illegal workers. For these reasons, a government‐​commissioned report by Westat estimated that illegal immigrants were 15 percent more likely to apply to firms using E‑Verify than their overall share of the labor force (6.2 percent compared to 5.4 percent). This analysis will assume that this rate has remained roughly the same.

E‑Verify can also erroneously deem legal workers “unauthorized,” which means that the number of denials is higher than the number of denials just for illegal immigrants. Legal workers can challenge an initial denial known as a “Tentative Non‐​Confirmation” (TNC) and try to prove their innocence, but only if their employers inform them of the error and don’t fire them or dump their application. If they don’t challenge or are unable to prove their identity if they do, the system still returns a “Final Non‐​Confirmation” (FNC), requiring the employer to fire them.

Westat estimated that in 2009, 6.3 percent of FNCs were for legal workers. While it has not released any other estimates, the government has reported the number of TNCs that legal workers overcome each year. This analysis assumes that these two rates are correlated and that the FNC error rate will reflect improvements in the TNC error rate. Subtracting out these erroneous FNCs gives us the actual number of illegal workers that E‑Verify has stopped.

The rapid decline in E‑Verify’s effectiveness

In fiscal year 2018, E‑Verify prevented the hiring of 16.1 percent of illegal workers. As Figure 1 shows, when E‑Verify was first being rolled out. Nearly all illegal workers who encountered the system received final non‐​confirmations, meaning that their employers had to lay them off. The rate fell continuously until FY 2014.

In absolute terms, E‑Verify failed to stop 1.8 million illegal hires in FY 2018, and it allowed nearly 12 million illegal hires to move forward since 2006. The number of illegal hires E‑Verify has prevented grew threefold since 2006, but the number of illegal hires E‑Verify allowed shot up 348‐​fold. Overall, E‑Verify stopped nearly 3 million illegal hires from 2006 to 2018—or 20 percent of attempted hires from illegal immigrants during that time.

The precipitous declines in effectiveness from 2007 through 2010 coincided with the first mandates of E‑Verify for federal contractors and employers in Arizona and Mississippi. Once E‑Verify became more common, illegal workers realized what was happening and quickly adjusted. Illegal workers can always apply using someone else’s ID and Social Security Number and obtain a job under the system.

Conclusion

E‑Verify has stopped relatively few illegal hires. Even those few illegal workers that E‑Verify has stopped probably found a job—either at a company not using E‑Verify or at an E‑Verify company after applying with a new identity. Overall, E‑Verify may have made illegal employment slightly more difficult, but not nearly enough to, as the cliché goes, “turn off the jobs magnet” that draws immigrants to the United States.