This is quite possibly the silliest study on immigration I've ever seen:

A new study by a liberal Washington think tank puts the cost of forcibly removing most of the nation's estimated 10 million illegal immigrants at $41 billion a year, a sum that exceeds the annual budget of the Department of Homeland Security.

The study, "Deporting the Undocumented: A Cost Assessment," scheduled for release today by the Center for American Progress, is billed by its authors as the first-ever estimate of costs associated with arresting, detaining, prosecuting and removing immigrants who have entered the United States illegally or overstayed their visas. The total cost would be $206 billion to $230 billion over five years, depending on how many of the immigrants leave voluntarily, according to the study.

According to the Washington Post, the study assumes "that tougher enforcement [of immigration laws] would induce 10 percent to 20 percent of undocumented residents in the United States to leave voluntarily."

Come on. Businesspeople are not stupid. They employ illegal aliens because they know employer sanctions are a joke.

If the feds started enforcing employer sanctions with any kind of seriousness, virtually every employer in the country would immediately fire any employee who does not have a valid social security number. If that happened, it seems obvious that the vast majority of illegal aliens, not just 10 or 20 percent, would quickly self-deport.

If fines on noncompliant employers were increased (as they should be), the net cost to the feds of beefed-up enforcement would be negligible.