We've gone and wasted all that time, effort and money on complicated approaches like border fences and stepped-up law enforcement and employer sanctions and moral arguments, and it turns out all we had to do to solve the problem of illegal immigration was wreck the economy a littler:
The number of illegal immigrants living in the United States dropped by 1 million people in two years, according to new estimates by the U.S. Department of Homeland Security.
The government believes 10.8 million illegal immigrants lived in the country in January 2009, down from a peak of nearly 12 million in 2007. If the official estimates are correct, not since 2005 has the population of illegal immigrants been as low as it was last year.
[. . .]
Most researchers agree that no matter the size of the population, which is notoriously hard to measure, the rate of illegal immigration dropped sharply during the recession. They disagree, however, on the causes.
"The number of new undocumented immigrants coming in has plummeted," Passel said.
Other researchers conclude the drop is not because fewer illegal immigrants are coming in, but because more are leaving.
If things get any worse, Mexico might be the one with the illegal immigration problem. Let's see how tolerant it is.