SAN DIEGO (Border Report) — The number of people crossing the border, who they are and where they come from has changed significantly during the last five years, according to new research.

“The rate of migration began to decrease in 2008 during the recession in the United States. It went on till 2018,” said Douglas Massey, a sociology researcher at Princeton University.

Massey said migration actually turned into a “negative flow” between those years.

“The population of undocumented Mexicans dropped by 1.5 million people who went back to Mexico.”

Doug Massey is the Henry G. Bryant Professor of Sociology and Public Affairs at the Princeton School of Public and International Affairs. (Princeton University)

Massey found that during President Barack Obama’s administration from 2009 to 2017, migration dropped to figures not seen in 40 years.

“In the 90s, migration to the United States was dominated by Mexican men looking for work, but since then we began seeing more migrants from Central America, although their numbers were still small,” said Massey. “They started coming in the 90s due to the wars in Central America created by U.S. intervention.”

Since 2018, a new era has emerged in migration, according to Massey.

“Before, migrants were in search of work opportunities, manual labor, but now, migrants are refugees and the besieged who aren’t looking for work, but are seeking refuge in the United States.”

Massey added that demographics among migrants have also changed.

“It’s not a migration of men looking for work, it’s now families, women and children, it’s working-age men who aren’t fleeing for job opportunities, but men who are escaping horrible things in their place of origin, this has become a pattern.”

According to Princeton University, Massey’s research focuses on international migration, race and housing, discrimination, education, urban poverty, stratification, and Latin America, especially Mexico.