Hundreds of thousands of undocumented migrants have been apprehended every year in recent years while trying to enter the US from Central American countries, including Honduras, Guatemala, and El Salvador. Mysteriously, however, the percentage of apprehended migrants from Mexico has dropped substantially. In 2004, US border patrol apprehended 1.1 million Mexicans, accounting for 9 out of 10 undocumented migrants that year. This number dropped to a low of 265 thousand in 2017 and then rose, to between 700 and 800 thousand in the early 2020s. So, what caused the number of undocumented Mexican migrants to plummet over time? Professor Jorge Dominguez recently set out to solve this mystery. Read Less
Despite Donald Trump’s recurrent mentions of Mexican immigrants during his 2016 Presidential campaign, Professor Dominguez notes that the apprehension of undocumented Mexicans had already fallen to 325 thousand before his election to the presidency. Therefore, his policies played no role in the long-term decline.
Having ruled out this possibility, one explanation could be increased border patrol. This enhanced enforcement may have deterred Mexican nationals from trying to enter the US illegally. While a study found that measures introduced between 2005 and 2010 deterred some migrants from travelling to the US, this only partly explains the observed decline.
The decline could also be linked to a failure of interdiction, which allowed more Mexicans to cross the border undetected. Yet statistics show that interdiction improved, while the number of apprehended Mexicans fell.
Another possible explanation for this mystery is that quality of life in Mexico has improved substantially, meaning that fewer people would be inclined to leave, but those who remained faced much higher criminal rates, especially homicides.
Changes to the US legal system may have also reduced undocumented Mexican migrants by simplifying immigration processes for temporary workers and their families. Changes in legislation increased the number of documented temporary workers from 81 thousand in 2000 to 897 thousand in 2019. This number plummeted during the COVID pandemic. However, the decline in undocumented migrants was steeper than the rise in legal migrants.
So, what may explain the mystery of vanishing undocumented Mexicans?
The answer is simpler than one might think. The average number of babies born in Mexico per woman declined from 6.75 in 1970 to 3.75 in 1990 and 2.4 in 2010. The use of contraception has more than doubled over the past 50 years, contributing to this reduction in births.
Professor Dominguez’s considerations suggest that empowering people in Central and South America to take control of their reproductive lives could have the greatest impact on undocumented immigration.
