Here is another consequence of the American economic crisis: the flow of undocumented immigrants to the United States has hit “net-zero.”

One million Mexicans said they returned from the US between 2005 and 2010, according to a new demographic study of Mexican census data. That’s three times the number who said they’d returned in the previous five-year period.

And they aren’t just home for a visit: One prominent sociologist in the US has counted “net zero” migration for the first time since the 1960s.

Experts say the implications for both nations are enormous – from the draining of a labor pool in the US to the need for a radical shift in policies in Mexico, which has long depended on the billions of dollars in migrant remittances as a social welfare cornerstone.

“The massive return of migrants will have implications at the micro and macro economic levels and will have consequences for the social fabric … especially for the structure of the Mexican family,” says Rodolfo Casillas, a migration expert at the Latin American School of Social Sciences in Mexico City.

Sociologist Douglas Massey provides more details about what has happened:

The migration explosion that since the 1970s had pushed millions of men, women, and children into the United States has fizzled, says Douglas Massey, a sociologist at Princeton University and codirector of the long-term, binational Mexican Migration Project. “We’re at a turning point, and what unfolds in the future remains to be seen. But I think the boom is over.”

Mr. Massey’s research shows that after the US recession hit, the illegal population fell from about 12 million to 11 million, where it has hovered since 2009. (About 60 percent of the illegal population is Mexican.)

Similarly, Homeland Security estimates released in March suggest that while the number of unauthorized immigrants living in the US grew 36 percent between 2000 and 2011, from 8.5 million to 11.5 million, that growth plateaued in 2010 and 2011.

“With no change in either direction, we’re roughly at a net zero,” says Massey, and adds that it’s something unseen since the late 1950s.

This bears watching. Now that I think about it, we have heard little about this topic on a national scale in recent months. Do the majority of Americans only care about this issue under certain circumstances? Thinking more broadly, does American news coverage focus on only a narrow set of issues (such as jobs, political responses and approval ratings, spending vs. accumulating debt, possible solutions) during an economic crisis rather than looking at the broad range of social spheres, including the relationships between the United States and other countries, affected by a downturn?