The number of immigrants who entered the country legally but then overstayed visas declined sharply after 9/11, according to a paper released earlier this week.
The paper found that visa overstays dropped by 73 percent over the first decade of the 2000s, from approximately 705,000 overstays in 2000 to 190,000 in 2009. Robert Warren, a former demographer for the U.S. Immigration and Naturalization Service (INS), co-authored the paper and a related report released in February.
The report showed that illegal immigration on a whole shrunk considerably in the 2000s, but that visa overstays in particular dropped more precipitously in the years after September 11.
The drop corresponds closely with enhanced security measures during that period. In the years immediately following the terrorist attack, the federal government overhauled the way that it handled foreign visitors, and the focus of immigration screenings became more centered on national security. In 2003, for example, the government put a system called US-VISIT into place, which recorded the fingerprints and photos of all non-citizens coming into the country.
The new data on visa overstays could help guide the immigration debate in Congress, as bipartisan groups of legislators in both the Senate and the House draft immigration reform bills.
The group of Democrats and Republicans working on reform in the Senate -- known as the "Gang of Eight" -- plan to combat illegal immigration with an array of enforcement measures, including increased border security and better tracking for people who overstay visas. Earlier this week, Sen. Marco Rubio (R-Fla.) wrote in an open letter to a Senate committee chair that the reform plan would include establishing "an effective entry and exit system," which would better track visitors to the U.S.
But since the number of visa overstayers has already fallen substantially, such a system -- particularly if it's expensive -- might not be as essential as once thought.
The country has been looking to improve tracking of visitors for some time. After 9/11, the federal government tasked the U.S. Department of Homeland Security (DHS) with building a new entry-exit system, using fingerprints or other physical data to keep tabs on visitors. But that type of system hasn't been feasible, according to DHS officials.
Homeland Security already has fingerprinting for foreigners upon entry, so it can track people who come into the country legally. But exit screening has proved trickier.
"The U.S. did not build its border, air and immigration infrastructure with exit processing in mind," David Heyman, DHS's assistant secretary for policy, wrote in a USA Today op-ed this February. "Airports don't have designated exit areas for departing passengers or specific checkpoints where a passenger's departure is recorded by an immigration officer, as many countries do."
The DHS does currently track exits, but it uses various databases and flight logs, and not a fingerprint system. In February, Homeland Security Sec. Janet Napolitano testified at a House committee hearing that creating a system based on fingerprints or other physical characteristics would be "extraordinarily expensive."