How large are visa‑overstay versus entry‑without‑inspection contributions to U.S. unauthorized population growth since 2015?
Executive summary
A preponderance of recent research finds that visa overstays have become an equal or larger source of net additions to the U.S. unauthorized population than entries without inspection (EWI) since the mid‑2010s, but the exact split varies by year and by data and methodology; for example, DHS reported that about 42% of the roughly 11 million unauthorized population in FY2022 originally entered legally and overstayed, while several academic and NGO estimates placed overstays above 50–60% of new additions in the 2014–2017 period [1] [2] [3]. Measurement challenges — incomplete exit records historically, different residual estimation methods, and pandemic data disruptions — mean precise, single-year attributions after 2019 are weakly supported by the public record [4] [5].
1. The headline numbers: multiple sources point to overstays as a major contributor
Government and research reports converge on the conclusion that visa overstays matter: DHS’s FY2022 summary estimated that about 42% of the roughly 11 million unauthorized population entered legally and overstayed (a stock measure) [1], while the Center for Migration Studies and scholars such as Robert Warren estimated that overstays exceeded EWIs for much of the 2010s and that overstays accounted for roughly 62% of newly undocumented arrivals in 2016–2017 and two‑thirds of new arrivals in 2014 [3] [2] [6].
2. Why the share of overstays rose: border enforcement, changing origin patterns, and air travel
Researchers attribute the rising share of overstays to sustained declines in unauthorized land crossings from Mexico since the 2000s, growing flows from other regions who arrive by air and then overstay, and the expansion of temporary visas (students, temporary workers, Visa Waiver Program travelers) that create more opportunities to overstay; the SSA review and Pew summaries both document a rising overstay share in recent years and note that overstayers increasingly come from outside Mexico and Central America [5] [7].
3. Measurement limits: residual methods, exit data gaps, and pandemic effects
All major estimates rely on residual methods or on DHS overstay reporting; historically the U.S. lacked a comprehensive exit‑tracking system and researchers had to impute departures, producing wide uncertainty [4] [8]. DHS has improved reporting since 2016, but experts warn that COVID‑era disruptions and methodological differences between DHS, CMS, academic groups, and NGOs make year‑to‑year comparisons after 2019 fragile [4] [1].
4. Contrasting findings and corrections: overstays aren’t uniformly growing every year
Not every study points to steady overstay growth; for instance, CMS published an analysis showing that after adjusting DHS counts for unrecorded departures, overstay population growth was near zero in 2016 — a corrective that narrows the claim that overstays automatically outpace EWIs in every single year [9]. Older enforcement arrest data presented by GAO showed more EWIs among arrested unauthorized workers in the early 2000s, underscoring how the balance has shifted over time and can differ by metric (arrests vs. net population growth) [8].
5. How to interpret “contributions to growth” since 2015: a balanced read
Taken together, the best available sources indicate that since roughly 2015 visa overstays have been a major — often majority — source of net additions to the unauthorized population, with point estimates ranging from about 40% of the stock (DHS FY2022) to 60–66% of recent annual new additions in CMS/academic work for mid‑2010s years [1] [2] [3]. However, the range reflects differing definitions (stock vs. flow), methodological choices, and known data limitations; therefore any single percent should be presented with caveats about uncertainty and year‑to‑year variability [5] [4].
6. Stakes and framing: why the split matters politically and for policy
Which pathway dominates shapes policy choices — border infrastructure and enforcement target EWIs while better visa tracking, visa policy, and adjudication focus on overstays — and both political actors and advocacy groups selectively emphasize one pathway to support policy agendas; reporting from fact‑checkers and policy groups highlights both the factual basis for the rising overstay share and the potential for selective framing to mislead if uncertainties are glossed over [10] [11].