171213-Feature

Blas Nunez-Neto –The Rand Blog — December 9, 2017  
The Big Border Security Question
The U.S. needs a better understanding of the number of illegal border crossings
    A U.S. senator I once worked for was fond of saying that you can’t manage what you can’t measure. This old management adage holds true across a variety of disciplines, and is something that members of Congress should keep in mind as they debate what a secure border looks like and what kind of security measures are needed along the U.S. border with Mexico this fall. Despite investing billions of dollars since 9/11, it is still a struggle to measure how effective U.S. border security operations are.
    The Department of Homeland Security has decades of statistics concerning apprehensions made by Border Patrol agents, which have reached modern lows in recent years. However, apprehensions are output measures – what they actually measure are the activity of the Border Patrol. They tell us very little about how the Border Patrol is actually performing.
    In fact, over the years DHS officials have sometimes pointed to both increases and decreases in apprehensions as evidence that the Border Patrol is being more effective. In order to actually understand how effective Border Patrol operations are, however, you need to know the number of people that attempted to cross the border illegally. Comparing the number of people who cross the border with apprehensions would let us know what the Border Patrol’s batting average is, or how many people who cross the border illegally actually evade apprehension and make it into the country successfully.
    The truth is that there is a limited understanding of how many people attempt to cross the border illegally each year. A recent DHS report acknowledged this fact, pointing to substantial discrepancies between internal Border Patrol estimates of border crossings – which are based largely on the physical observations of agents – and a report commissioned by DHS that used statistical techniques based on survey responses and apprehensions data to estimate the overall flow of people across the border. While both methods appear to show that the Border Patrol has become more effective in identifying and apprehending illegal border crossers over time, the DHS report notes that they are still looking for ways to help better understand what the overall flow across the southwest border is. This is key, because without better estimates for the total number of crossings it is impossible to measure how successful U.S. border controls are. […]  
    Without being able to measure U.S. success at identifying and apprehending individuals attempting to cross the border illegally, policymakers and members of Congress may never be able to adequately manage America’s border security programs. This is perhaps one of the reasons why, despite the billions that have been spent on securing the border since 9/11, the U.S. still struggles to define what a secure border looks like.