The 1986 passage of the Immigration Reform and Control Act -- which granted amnesty to 2.7 million undocumented immigrants while simultaneously tightening border controls and increasing penalties for employers who hire illegal workers -- did not change long-term patterns of undocumented migration to the United States, according to a study published in the August issue of the journal Demography.
Economists Pia Orrenius and Madeline Zavodny found that apprehensions of persons attempting to cross the U.S.-Mexico border illegally declined immediately following passage of the law but returned to normal levels during the period when undocumented immigrants could file for amnesty and the years after.
They based their analysis on U.S. Immigration and Naturalization Service (INS) data on apprehensions between 1969 and 1996. To examine the impact of the amnesty program on illegal border crossings, their calculations take into account changes in border patrol enforcement hours, seasonal variation in migration, wage differences between the U.S. and Mexico as well as trends in the number of visas granted.
The number of migrants who enter legally but overstay their visas is not reflected in INS apprehension data. But other research has shown that the flow of undocumented immigrants is highly correlated with the number of INS apprehensions, making it a "useful proxy" for illegal migration trends, Orrenius reported.
Orrenius and Zavodny found that INS apprehensions declined by about 11 percent immediately following the passage of IRCA. These results suggest that the amnesty program did not lead to a surge in new undocumented immigration, as some critics have charged, they wrote.
"If anything, IRCA reduced the number of undocumented immigrants in the short run, perhaps because potential migrants thought that it would be more difficult to cross the border or to get jobs in the U.S. after the law was passed," said Orrenius.
The decline may also reflect a temporary drop in "circular" migration-the flow of undocumented immigrants who usually reside in the United States but temporarily return to Mexico to visit relatives.
These migrants may have postponed their travel until they were legalized or skipped traveling entirely because they perceived border crossing was more difficult after the law's passage, the authors speculated.
While IRCA led to a short-term decline in illegal migration, their findings suggest that it failed to discourage migrants in the long run.
"Apprehensions were similar before passage of the amnesty and post-IRCA, even though some 2 million Mexicans were legalized," said Orrenius. " This evidence is consistent with a rise in illegal immigration in the years after the amnesty."
Orrenius and Zavodny are researchers at the Federal Reserve Bank of Dallas and Atlanta, respectively. The research was undertaken independently.
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