"The number of illegal immigrants in the USA has fallen sharply as state and federal officials intensify a crackdown on undocumented migrants and jobs grow scarce in the faltering economy, according to a report Wednesday by a group that advocates reduced immigration.

Using Census data, the Center for Immigration Studies (CIS) estimates that the illegal immigrant population dropped by 10% to 11.2 million from August 2007 through May.

Pat Reilly, spokeswoman for Immigration and Customs Enforcement, cites her agency's workplace raids, deportations and efforts to track down illegal immigrants with criminal records. Tougher enforcement "has made entering and staying in the United States illegally less attractive as the probability of being arrested and detained is greater than ever before," she says."

Among the findings:

• Our best estimate is that the illegal immigrant population has declined by 11 percent through May 2008 after hitting a peak in August 2007.

• The implied decline in the illegal population is 1.3 million since last summer, from 12.5 million to 11.2 million today.

• The estimated decline of the illegal population is at least seven times larger than the number of illegal aliens removed by the government in the last 10 months, so most of the decline is due to illegal immigrants leaving the country on their own.

• One indication that stepped-up enforcement is responsible for the decline is that only the illegal immigrant population seems to be affected; the legal immigrant population continues to grow.

• Another indication enforcement is causing the decline is that the illegal immigrant population began falling before there was a significant rise in their unemployment rate.

• The importance of enforcement is also suggested by the fact that the current decline is already significantly larger than the decline during the last recession, and officially the country has not yet entered a recession.

• While the decline began before unemployment rose, the evidence indicates that unemployment has increased among illegal immigrants, so the economic slow-down is likely to be at least partly responsible for the decline in the number of illegal immigrants.

• There is good evidence that the illegal population grew last summer while Congress was considering legalizing illegal immigrants. When that legislation failed to pass, the illegal population began to fall almost immediately.

• If the decline were sustained, it would reduce the illegal population by one-half in the next five yea

New Enforcement Efforts. When efforts to legalize illegal immigrants failed in the U.S. Senate last summer, Secretary of Homeland Security Michael Chertoff and Commerce Secretary Carlos Gutierrez stated that, “until Congress chooses to act, we’re going to be taking some energetic steps of our own.”⁴ They emphasized that in addition to better policing of the border, the government was also going to do more in terms of interior enforcement, particularly pursuing employers who hire illegals.

Even before the legalization was defeated in June 2007, the administration was doing much more to enforce the law. The fenced portion of the U.S. border has increased significantly in the last 18 months and the number of Border Patrol agents has more than doubled in recent years to over 16,500. The number of detention beds used to hold aliens has more than doubled since 2000 to over 30,000. In 2007, 426 local law enforcement personnel participated in the 287(g) program, which trains police and allows them to enforce immigration laws.⁵ The number of aliens removed (including deportations) has increased significantly in recent years. In 2007, 285,000 aliens were removed, nearly double the number in 2002.⁶ Immigration and Customs Enforcement is likely to match its 2007 total through 2008.⁷

The E-Verify program, which allows employers to screen workers to see if they are authorized to work in the country, now covers about one out of 10 new hires in the country.⁸ Worksite enforcement has seen some of the largest increases in recent years, with the number of criminal and administrative arrests increasing more than five-fold since 2004.⁹

In many ways these efforts are still quite modest, and represent large relative increases from what was a very low level of enforcement. Nonetheless, they do constitute a more comprehensive approach to enforcement, both at the border and within the United States. They also represent a significant departure from a policy of non-enforcement during the Clinton administration and most of the Bush administration.

State and Local Enforcement Efforts. Over the past year, many state and local governments have acted to buttress federal efforts to enforce immigration laws. A good deal of debate has typically surrounded these proposals. Even when such initiatives fail to pass a state legislature or city council, local media, particularly foreign-language media, often cover these debates extensively. And while most proposals have not passed, some significant measures have been adopted. These include Georgia, Missouri, Arizona, and Oklahoma, which now require some employers to use the E-Verify system in order to obtain business licenses or government contracts. They also include increased efforts to use local police to enforce immigration laws. Some local governments have even tried to make it illegal for landlords to rent homes to those in the country illegally.