Department of Homeland Security: Reporting on Border Security Metrics Could Be Improved

What GAO Found

The National Defense Authorization Act for Fiscal Year 2017 (2017 NDAA) requires the Department of Homeland Security (DHS) to develop an annual report containing 43 specific metrics to measure the effectiveness of border security. In its 2021 Border Security Metrics Report, DHS reported on 37 of 43 metrics, the same set of metrics in DHS's 2019 report. As shown below, GAO found that 21 of the 37 metrics in the 2021 report generally corresponded with their definitions in the 2017 NDAA—three more than in its 2019 report.

Department of Homeland Security's (DHS) Reporting on the 43 Metrics Required by the National Defense Authorization Act for Fiscal Year 2017 (2017 NDAA)

DHS may be missing opportunities to fully report the metrics and improve the usefulness of the report. DHS components collect the data that underlie the metrics, but GAO found that in some cases, DHS did not fully report available data. For example, DHS reported data on passenger inspections, but did not report available data on cargo and commercial traffic, as outlined in the 2017 NDAA. By engaging with DHS components that collect relevant data, DHS could more fully report the metrics as defined by the 2017 NDAA. Additionally, DHS did not generally provide periodic briefings to Congress to help refine its metrics reporting, as its 2021 report states it would do. GAO identified instances where such engagement could help DHS identify next steps and address challenges it has faced reporting metrics. Such engagement could also help DHS ensure the information it reports is useful to Congress.

DHS improved the quality of some information in its 2021 report by implementing a prior GAO recommendation to include measures of statistical uncertainty for all metrics that rely on its statistical model. Implementing GAO's remaining prior recommendations to develop and implement a process to systematically review the reliability of data and then communicating relevant limitations would position DHS to maximize the quality of information. It would also provide Congress and the public with contextual information needed to evaluate the metrics.

DHS uses a statistical model of deterrence—the rate at which individuals who are apprehended attempting to cross the border decide not to make another attempt—to report three metrics related to unlawful entries. GAO found that DHS did not assess and update its deterrence model between when it was developed in 2016 and the 2021 report. However, DHS data show that aspects of the population of individuals attempting to unlawfully cross the border have changed, including by volume and country of origin. Those changes increase the risk that the deterrence model is no longer as reflective of current border conditions.

Why GAO Did This Study

The U.S. has approximately 6,000 miles of land borders, 95,000 miles of coastline, and more than 300 ports of entry where travelers and cargo are inspected. Securing U.S. border areas is a key part of DHS's mission. Its ability to measure border security activities is essential to managing its responsibilities effectively.

The 2017 NDAA requires DHS to report annually on 43 border security metrics. The act also includes a provision for GAO, within 270 days of receipt of the first report and biennially for the following 10 years, to review and report on DHS's report.

GAO issued its initial report in March 2019. This third report evaluates DHS's 2021 Border Security Metrics Report compared to its 2019 report. Specifically, this report assesses DHS's 2021 report for (1) progress since 2019 in reporting the metrics outlined in the 2017 NDAA and engagement with its components and Congress on the report, and (2) efforts to improve the quality of information in DHS's 2021 report. To do this, GAO assessed the methodology and data in DHS's report, analyzed DHS's use of statistical models, and interviewed officials from DHS offices and components involved in developing the metrics.