Expanding Access to Lawful Migration Reduces Unlawful Migration - Study

Michael A. Clemens, April 2024

"An increasing number of migrants attempt to cross the US Southwest border without obtaining a visa or any other prior authorization. 2.5 million migrants did so in 2023. In recent years, responding to this influx, US officials have expanded lawful channels for a limited number of these migrants to cross the border, but only at official ports of entry. These expanded lawful channels were intended to divert migrants away from crossing between ports of entry, by foot or across rivers, thereby reducing unlawful crossings. On the other hand, some have argued that expanding lawful entry would encourage more migrants to cross unlawfully. This study seeks to shed light on that debate by assessing the net effect of lawful channels on unlawful crossings. It considers almost 11 million migrants (men, women, and children) encountered at the border crossing the border without prior permission or authorization. Using statistical methods designed to distinguish causation from simple correlation, it finds that a policy of expanding lawful channels to cross the border by 10 percent in a given month causes a net reduction of about 3 percent in unlawful crossings several months later. Fluctuations in the constraints on lawful crossings can explain roughly 9 percent of the month-to-month variation in unlawful crossings. The data thus suggest that policies expanding access to lawful crossing can serve as a partial but substantial deterrent to unlawful crossing and that expanding access can serve as an important tool for more secure and regulated borders."