One aspect of DHS’s border security work is measuring effectiveness. For decades, DHS and the legacy INS have used apprehensions as their primary proxy indicator of border security, but apprehensions are a problematic measure. In recent decades, the Department has begun to develop a number of additional indicators that, together, provide additional insight into the state of border security. These additional indicators remain a work in progress. DHS has chosen to release these new indicators to be responsive to Congress and others interested in the state of border security.
While DHS employs a number of concrete metrics to track border security operations, it is difficult to precisely quantify illegal flows because illegal border crossers actively seek to evade detection, and some flows are undetected. As a result, any effort to quantify illegal flows or calculate an overall enforcement success rate must rely on one or more estimation techniques. Measurement is also difficult because of the diversity and complexity of the enforcement mission along the United States’ 2,000-mile land border with Mexico.
Since 2001, border patrol and technology resources at the border have increase dramatically, including resources as a result of the 2006 Secure Border Act. Both traditional border metrics and the preliminary findings based on new indicators indicate that crossing the border illegally has gotten more difficult since then, but illegal entries continue.
In light of still-unresolved concerns about some of this research, the Department also continues to pursue additional analytical frameworks to produce the most accurate possible estimates of the current state of border security. This additional work focuses on USBP’s efforts to increase situational awareness at the border—an effort with important operational implications that also yields increasingly robust observational estimates of border security.