Mexican Border Crossings Lowest in Decades, Study Finds

​A new study by researchers at Princeton University's Woodrow Wilson School of Public and International Affairs upends a lot of the conventional thinking about the effects of U.S. immigration policy -- most notably the contention that harsher security measures along the U.S.-Mexico border have kept immigrants out of southwestern American states.

As California Watch reports, the study by Douglas Massey and Karen Pren reveals that fewer illegal border-crossers were caught last year than at any other time in decades. Legal entries into the country across the southern border have also declined, going from 219,000 in 2002 to 139,000 in 2010.

But the impregnability of the border appears to have had another effect that anti-immigration activists wouldn't be too happy about. The study's authors found that the dismantling of a guest-worker program, as part of national immigration-law reforms in 1965, has led to fewer of the immigrants who come to the U.S. ever returning to Mexico.

The result: Our country's Latino population has risen from 10 million in 1965 to more than 50 million today, at least 10 million of whom are estimated to lack official immigration documents.

The policy debates dogging immigration reform -- which will disproportionately affect western states such as California, Arizona, Texas, and New Mexico -- are far from simple. But the new study provides compelling evidence that a quasi-militarized southern border isn't producing the outcomes anybody wants.

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