With today’s news that U.S. Customs and Border Protection (CBP) encountered migrants crossing the U.S.-Mexico border without authorization 1.66 million times in fiscal year (FY) 2021 (a number that rises to 1.73 million when interactions at ports of entry are included), much is being made of the fact that these numbers top the 1.64 million apprehensions that occurred in FY 2000, making this the highest year on record. While there is no doubt that 2021 represents a high one for border arrivals—reflecting both an increase from recent years and diversification of nationalities—this does not necessarily mean that more migrants were intercepted or illicitly entered the country than was the case 21 years ago.

The determination of which year represents the record year is not clear cut and is complicated by a number of factors, not least that there is no measurement of unique individuals apprehended in the 1990s and early 2000s. Apprehensions represent events, not individuals, and it has only been in recent years that the Department of Homeland Security (DHS) has begun tracking enforcement activities by the number of unique individuals intercepted, making an apples-to-apples comparison with 2000 unfeasible.

Both 2000 and 2021 were marked by a high rate of recidivism—in other words, migrants who had been encountered and turned back by the Border Patrol trying to cross again (and sometimes multiple times). This means that, in both years, far fewer than 1.7 million unique individuals crossed the border without authorization (see section on recidivism for further discussion). Further, the number of migrants who were able to successfully enter the United States unlawfully without being apprehended was significantly higher in FY 2000 than now—a metric Border Patrol encounter reporting does not address.

More than 2.1 million unauthorized migrants would have crossed into the United States without being apprehended in FY 2000, based on that year’s estimated 43 percent apprehension rate. Official data have not been released on the number of unauthorized migrants who avoided apprehension in FY 2021. But media reports of Border Patrol numbers cite a figure of 400,000 “got-aways” (those detected but not intercepted by the Border Patrol) for FY 2021. Got-aways represented 74 percent of estimated successful unlawful entries in FY 2018. If that trend has held and the got-away numbers cited for 2021 are accurate, there were about 540,000 successful unlawful entries in FY 2021—less than one-fourth the estimated 2000 total.

Read the full article about migration at the U.S.-Mexico border by Jessica Bolter at Migration Policy Institute.