A report from the Center for Immigration Studies concludes that illegal immigrants have left the US in large numbers, thanks to enforcement efforts at federal and state levels over the past nine months.  The change coincides with the rejection of the comprehensive immigration bill considered by Congress and abandoned last July.  The CIS contends that this created a disincentive that pushed almost a million illegals back across the border:

A report released yesterday by a Washington think tank that advocates stricter limits on immigration says the number of illegal immigrants in the country appears to have declined significantly over the past year, at least partly because of the chilling effect of stepped-up enforcement.

The study by the Center for Immigration Studies based its findings on census data that indicate that the number of less-educated, working-age Hispanic immigrants, defined as 18-to-40-year-olds with a high school diploma or less, has dropped by more than 10 percent, or about 830,000 people, since last August.

Previous research suggests that a large share of less-educated foreigners is in the country illegally and that it makes up the bulk of the illegal immigrant population. Furthermore, although earlier declines in the number of these Hispanic immigrants have been linked to a rise in their unemployment rate, the current drop-off began last year almost immediately after Congress abandoned legislation to legalize undocumented immigrants and six months before any significant rise in their unemployment rate had occurred.

During the same period, the number of foreigners who were more educated or non-Hispanic, and therefore far less likely to be illegal immigrants, continued to rise or hold steady.

“Chilling effect” of enforcement?  It should be the normalizing effect of enforcement.  The government should have been taking these steps all along.  Had they done so, the issue would not have been anywhere near as acute as it currently is, and we could be already dealing with temporary worker systems or other options for labor in the agricultural industry, at least.

The methodology has created some controversy among researchers, however.  The CIS uses an indirect method of calculating the number of illegal immigrants based on a particular demographic ratio, which assumes that ratio remains constant.  Critics don’t reject the method entirely, but note that its assumption could prove incorrect, and that would result in significantly different numbers than CIS reaches.

Still, other data indicates that they have this diagnosed properly.   The Border Patrol reported a 20% decrease in apprehensions during this period despite enhanced resources, indicating a decrease in border crossings.  States like Arizona that have instituted tough sanctions against employers who either knowingly hire or fail to use eVerify to reject illegal workers have seen population decreases in areas where illegal immigrants live.

More study needs to be done, but the data thus far shows that enforcement works, especially at the strongest magnet for illegal immigration: employment.  The CIS researchers think that enforcement alone, even without tougher border security, could cut the number of illegal immigrants in half over the next five years.  With a stronger border and even better scrutiny, that pace could accelerate even further.