Back to the Future? December 2019 Apprehensions Recall Past Trends

The CBP data shows that the decline in the number of families arriving at the border drove the sharp drop shown in Figure 1. As Figure 2 shows, the number of family units fell from 84,486 in May 2019 to 8,602 by the end of the year, which correlated with the drop in overall Southwest border apprehensions. However, apprehensions have not shown a further decline because single adults remain a stable and sizable portion of migrants arriving at the border. Although single adult apprehensions increased from 22,925 in September 2018 to 36,895 in May 2019, they dropped to 21,006 in December 2019, a level that largely remained consistent since August 2018.

Comparing the percentages of family unit and single adult apprehensions shows the same trend, with single adults making up an increasing percentage of the total as the percent of family units fell through December 2019. As Figure 3 shows, families dropped from 64% of all apprehensions in May 2019 to 26% in December 2019. In contrast, single adult apprehensions remerged as the largest percentage of apprehensions, growing from 28% in May 2019 to 64% in December 2019. These percentages mark a complete reversion to the levels seen in April 2018 when families formed 25% of all apprehensions and single adults made up 64%. Meanwhile, unaccompanied children maintained a steady percentage of the overall totals, between 7% and 10%.

Mexican nationals reemerged as the largest group of migrants apprehended at the U.S.-Mexico border between October and December 2019. As Figure 3 shows, Mexican citizens formed 46% of apprehensions, 86% of whom were Single Adults.  In contrast, Guatemalan, Honduran, and Salvadoran migrants formed 38% of apprehensions, 44% of whom were Single Adults and 41% of whom were Family Units. While these demographics may change over FY2020, they suggest migration to the U.S.-Mexico border may be reverting to pre-FY2016 patterns when most migrants arriving at the border were single Mexican adults.

It is unclear whether or how Mexico’s efforts to expand its migration enforcement operations have affected these trends. Mexican government data shows that the number of its migrant apprehensions and returns grew between December 2018 and June 2019¹, with apprehensions increasing from 6,278 to 31,416 during this period. After Mexico expanded its enforcement operations, the number of U.S. apprehensions at the Southwest border began to decline, indicating these measures may have prevented or deterred some migrants from reaching the U.S.-Mexico border. However, the Mexican government apprehended and returned fewer migrants between June and December 2019, with apprehensions decreasing from 31,416 to 9,404 during this time. This trend suggests that the Mexican government’s enforcement measures may have produced diminishing results in reducing overall migrant flows, especially when dealing with single adults who continued to arrive at the border in steady numbers.

Similar trends appear when comparing MPP returnees to Southwest border apprehensions.² As Figure 3 shows, Transactional Records Access Clearinghouse data on MPP-related immigration court cases³ shows that the increase in MPP returnees corresponded with a decrease in family apprehensions between January and September 2019. However, the TRAC data also shows that monthly MPP returnees decreased from 12,457 in August 2019 to 3,308 in December 2019, completely reversing the program’s growth during the spring and summer. Much like Mexican enforcement efforts, this decline suggests that MPP has also produced diminishing results as fewer families arrived at the U.S.-Mexico border.

This final point raises questions about the Trump administration’s capacity to keep southwest apprehensions low going forward. The administration’s efforts to limit asylum access at the border and push Mexico to increase enforcement actions against migrants has contributed to the decline in family unit apprehensions, which will be strengthened by the implementation of the Asylum Cooperation Agreements with El Salvador, Honduras, and Guatemala. However, the persistent levels of single adult apprehensions show that these enforcement measures could struggle to further reduce migrant flows or deter populations that fall outside their scope. This population could include economic migrants seeking work in the interior of the United States or former asylum seekers who decide to enter and continue into the United States instead of presenting themselves to U.S. authorities to seek asylum. The emergence of a new caravan from Honduras in January 2020 shows a pool of Central Americans who are seeking a means to migrate to the North, despite these measures. If these migrants begin arriving to the U.S.-Mexico border through these means, Southwest border apprehensions may rise in 2020.

^{1 This period corresponds with the Mexican government’s expansion of migration enforcement in response to the Trump administration’s threat to impose tariffs on the country unless it stemmed the entry of Central American migrants into its territory.
2 For an overview of the Migration Protection Protocols, see: https://bipartisanpolicy.org/blog/the-trump-administrations-responses-to-central-american-migration/
3 As we noted in our analysis of publicly available MPP data, TRAC reviews court records from the Executive Office for Immigration Review to track MPP-related immigration court cases between January 2019 and the present. The TRAC database is the only source of MPP data that tracks the number of migrants returned to Mexico through the program. The U.S. government has not produced monthly estimates of MPP returns.}