In a recent post on E‑Verify, the system for conducting federal immigration background checks on American workers hired to new jobs, I criticized an assumption on the part of DHS Assistant Secretary for Policy Stewart Baker that the 5.3% of people who receive “final nonconfirmations” from the system are illegal immigrants:

Baker’s conclusion that the 5.3% of workers finally nonconfirmed are illegal workers is without support. The statistic just as easily could show that the 5.3% of law-abiding American-citizen workers are given tentative nonconfirmations, and they find it impossible to get them resolved. More likely, some were dismissed by employers, never informed that there was a problem with E‑Verify; some didn’t have the paperwork, the time, or the skills to navigate the bureaucracy; and some were illegal workers who went in search of work elsewhere, including under the table.

Yesterday at a meeting of the DHS Data Privacy and Integrity Advisory Committee, a new data point opened a small window onto the situation of the 5.3%. To review, 94.2% of the workers submitted to the system are confirmed as eligible for work within 24 hours. Of the 5.8% tentatively nonconfirmed, .5% successfully contest their nonconfirmations, leaving us with 5.3% who receive final nonconfirmations for reasons yet unknown.

Staff of the DHS’ U.S. Citizenship and Immigration Services bureau reported yesterday that they had recently added a “doublecheck” on tentative nonconfirmations, asking employers to review the data they had entered for errors. During the two months this has been in place, it has lowered the tentative nonconfirmation rate by 30%. That’s right — 30% of the tentative nonconfirmations had been caused by employers’ fat fingers. (“Fat fingers” is not a knock on employers’ fitness — it’s a techie term for data entry errors.)

If we assume that the figures recited above are from a period before the new fat-finger doublecheck, the 5.8% tentative nonconfirmation rate should have dropped 1.74% since the double-check was implemented. Next, assume (generously) that all of the .5% successfully contesting their tentative nonconfirmations were part of this cohort — the victims of employers’ fat fingers. This leaves 1.24% of workers submitted to E‑Verify during this period who were eligible to work but victims of employers’ data entry errors — and who failed to contest their nonconfirmations.

There is plenty of room for error in this extrapolation, and I’ll happily publish refinements or corrections to what I’ve written here, but it looks like more than 1 in 100 employees are tentatively nonconfirmed by E‑Verify and go on to final nonconfirmation even though they are eligible to work under the immigration laws. That’s a huge percentage considering that millions of Americans’ employability is on the line. The burden is on DHS and other proponents of electronic employment eligibility verification to figure out what’s going on and to fix it.

E‑Verify is not ready for prime time, and we wouldn’t want it even if it was.