Border securityIncreasing effectiveness of border patrols by making them random

Published 17 April 2012

A new study finds that combining historical data on illegal border crossings with unpredictability and randomness of patrols would be the most effective approach to increase interdiction of illegal border crossers

DHS is responsible for protecting U.S. borders against terrorist threats, criminal endeavors, illegal immigration, and contraband. Budgetary and other resource constraints, however, create a situation in which it cannot “see and be” everywhere at once. DHS says that in response, the Office of Border Patrol (OBP) is investigating how pattern and trend analysis and systematic randomness may be used to position border security personnel and equipment in the places and at the times they will be most effective.

A RAND study examined how these techniques affect interdiction rates, incorporating results from a RAND-developed agent-based simulation model of the interaction of border patrol agents and illegal smugglers. The model allowed an exploration of how interdiction rates differ across thousands of scenarios that vary by the number of patrols, the rate of illegal flow, the size of the border, and the approach OBP takes to using pattern and trend analysis and systematic randomness. DHS says that the analysis shows how approaches that combine these two techniques yield higher interdiction rates than approaches using either technique alone, and it identifies circumstances in which combined approaches are competitive with perfect surveillance.

The key finding of the RANd study:

Resource allocation approaches that combine pattern and trend analysis and systematic randomness yield higher interdiction rates than approaches using either strategy alone.

  • Appropriate combinations of pattern and trend analysis and systematic randomness can, in some circumstances, yield interdiction rates that are competitive with “perfect surveillance” (perfect hindsight of historical crossings — both successful and unsuccessful).
  • The benefits of combining pattern analysis and systematic randomness appear particularly strong when the number of available patrols is high relative to the rate of illegal flow but low relative to the size of the border — the circumstances confronted by many OBP stations.

Regardless of strategy, interdiction rates are better explained by relative measures rather than by absolute measures.

  • Relative measures, such as coverage and capacity, are more predictive of interdiction rates than absolute measures, such as the number of patrols, the size of the border, or the number of smugglers.
  • OBP stations group in counterintuitive ways when compared using relative measures, such as coverage and capacity. For example, some northern and southern border stations appear more similar than when they are compared absolutely by the number of patrols, the number of apprehensions, or the length of the border.

The study makes these key recommendations:

  • The Office of Border Patrol (OBP) should catalog all detections of illegal border crossings, even those that do not result in interdiction, and incorporate them into analyses of historical patterns and trends
  • OBP should institute a plan to schedule patrols based on daily pattern and trend analysis and systematic randomness. This plan should include a phase of experimentation using randomized control trials.
  • OBP should develop a management tool to compare its stations based on relative measures, such as coverage and capacity.