Increased enforcement and the declining U.S. economy have contributed to the lowest levels of border arrests since the 1970s according to Border Patrol Statistics. From October 2008 through February 2009, agents arrested 195,000 trying to cross the Mexican/U.S. border, which is a 24 percent decrease from the same period a year ago.

U.S. Border Patrol spokesman Ben Vik had a simple response when talking about a two-day stretch in December that saw no apprehensions: "We're in shock."

The border fence that is still under construction has done some to slow the migration, but the economy has played the biggest role.

"A lot of people who would have come here illegally and stayed illegally are not bothering to come to the U.S.," said Demetrios Papademetriou, president of the Migration Policy Institute, in a L.A. Times article. "The information that they are getting basically says there are no opportunities here."

More can be found on this story at the Los Angeles Times.

Updated: Thu, Apr 8th 2010 @ 10:51am EDT