How do 'encounters' relate to net migration and the measurement of 'gotaways' at the U.S.–Mexico border?
Executive summary
Encounters are the official counts of migrants who meet U.S. officials at or between ports of entry and are the primary observable input for migration statistics; they do not by themselves measure total net migration because they omit people who cross without being detected, the so‑called “gotaways” [1][2]. Estimating gotaways requires modeling and historical ratios applied to encounter data, which produces widely varying estimates and fuels competing political narratives about border control success and net migration [3][4].
1. What “encounters” mean and what they include
“Encounters” is CBP’s catchall metric for removable noncitizens who are apprehended or processed at ports of entry, and it explicitly aggregates USBP Title 8 apprehensions, Office of Field Operations inadmissibles, and Title 42 expulsions — in short, the visible contact points between migrants and authorities that CBP reports publicly [1][5]. Migration scholars and agencies also use the term “irregular encounters” to refer to expulsions and apprehensions at the U.S.–Mexico border, a framing that captured nearly 2.5 million such events in FY2023 according to policy research summaries [6].
2. Why encounters don’t equal total entries or net migration
An encounter only confirms a migrant was contacted by an official; it cannot reveal how many people crossed undetected or later remained in the country, so encounters are an incomplete measure of net migration — the net change in population from migration flows [1][2]. DHS and independent researchers acknowledge that entries without inspection (gotaways) are “inherently difficult to measure,” and DHS has not publicly released a detailed, consistent gotaways time series in recent years, forcing analysts to infer unseen flows from encounters and other indirect indicators [3].
3. How “gotaways” are estimated and the limits of those methods
To estimate gotaways, researchers and agencies generally apply historical ratios that relate observed encounters to modeled unobserved entries; Brookings, for example, used ratios from 2015–2019 to estimate 2025 entries without inspection in the tens of thousands (22,000–39,000) based on much lower encounter counts that year [3]. Those estimates are sensitive to the baseline period, enforcement changes, and technological detection, so small changes in assumptions produce large swings in the estimated size of gotaways — a methodological constraint acknowledged by Brookings and visible in divergent public claims [3].
4. Policy shifts, encounters and why gotaway estimates change
Policy tools such as Title 42 expulsions, parole programs, app-based port appointments and enforcement surges visibly alter encounter totals and the behavior of migrants, which in turn changes the modeled ratio between encounters and gotaways; for example, Title 42 expulsions coincided with different gotaway patterns and its end was associated with fluctuating gotaway rates in public reporting [7]. DHS has claimed a roughly 60% reduction in estimated gotaways from FY2023 to FY2024 tied to policy actions and rule changes, while other observers point out that steep drops in reported encounters under later policies can reflect administrative exclusions of humanitarian reception rather than a pure drop in crossings [4][8].
5. The politics of measurement and competing narratives
Because encounter counts are concrete and regularly published by CBP, they become the headline metric for administrations and critics alike; political actors highlight decreases or spikes to advance security, humanitarian, or enforcement narratives, and partisan reports can frame “gotaways” as evidence of chaos or success depending on the underlying agenda [4][9]. Independent analysts and NGOs caution that low encounter totals can reflect policy design choices and reduced humanitarian processing as much as fewer attempted crossings, underscoring the need to read encounter and gotaway figures against enforcement rules and data‑production practices [8][6].
6. What this means for understanding net migration
Encounters provide a necessary but insufficient window onto net migration: they measure the visible portion of crossings and are indispensable for short‑term operational metrics, yet without transparent estimates of gotaways and post‑encounter outcomes (reentries, removals, stays) one cannot derive a robust net migration figure solely from encounter data [1][3]. Public reporting gaps — such as the lack of a continuous DHS time series on gotaways — and reliance on historical ratios mean any net migration estimate based on encounters must be treated as provisional and sensitive to policy and modeling choices [3].