Undocumented Migration Does Not Drive Crime Study Finds
Across more than 100 American cities, neighborhoods that saw their undocumented populations grow also saw property crime and violent crime fall. The analysis covered 11,500 neighborhoods and 46 million people, making it the largest study of its kind. Between 2010 and 2018, the average share of undocumented residents in a neighborhood dropped from 5.6 percent to 4.8 percent. During that same period, crime did not rise in the places where undocumented populations grew. This reverses a widely held assumption that undocumented immigrants commit more crimes than citizens or documented immigrants.
The findings were published on August 10 in the Journal of Urban Affairs and reported in Nature on August 14, 2026. [2] Charis Kubrin, a criminologist at the University of California, Irvine, and co-author of the study, said the work is the first to analyze these numbers across neighborhoods using such a diverse national sample. [3] Neighborhoods are very proximate spaces to people, Kubrin noted, and that is where perceptions form about who lives nearby and whether a community feels safe.
What the Data Actually Shows
Property-related crime and assaults both fell in neighborhoods where undocumented populations grew. Robberies, however, showed a different pattern — they increased slightly. This mixed result is worth attention because it complicates the simple story that immigration either causes crime or prevents it. The researchers had to work with estimates rather than exact counts, because undocumented immigrants are by definition difficult to count. No country has a precise registry of people who entered illegally or overstayed a visa.
Alexis Piquero, a criminologist at the University of Miami in Coral Gables, Florida, said earlier studies used samples of people or places in a specific jurisdiction. [4] The new work has a much larger reach, he said, which gives it greater weight. Ben Brindle, a senior researcher with the Migration Observatory project at the University of Oxford, UK, said the findings fit the picture seen in UK studies. [6]
The researchers gained access to non-public demographic data for 46 million people through a US federal statistical research data center. To estimate undocumented status, they excluded US citizens and people born in the country. They also excluded those receiving public health insurance, enrolled in higher education, or married to a US citizen, because those individuals are likely authorized visa holders or permanent residents. This method produced estimates that Kubrin said are quite similar to those of the Department of Homeland Security. [7]
Who Will Use This First
City officials and police departments are the most likely first users of these findings. For years, local governments have made policy decisions based on the assumption that undocumented immigration strains public safety resources. This study gives them a data-backed reason to reconsider those assumptions. The neighborhood-level focus matters here, because citywide averages can hide what happens in specific communities. A neighborhood where undocumented residents settle is the scale at which people actually experience safety or fear.
Policymakers at the federal level may also take note, though the study does not address immigration policy directly. The research covers the years 2010 to 2018, a period that includes significant shifts in enforcement priorities and border policies. What the data shows is that despite these policy changes, the relationship between undocumented population growth and crime stayed consistent. That consistency across time and across more than 100 cities strengthens the case that the finding is not an artifact of one particular policy environment.
The academic community will likely use this study as a reference point for future research. Piquero noted that measuring undocumented populations is inherently difficult, so researchers have developed various estimation methods. This study’s method, using federal data center access, represents one of the most comprehensive approaches to date. Future studies can build on this by examining other outcomes beyond crime, such as economic contributions or community cohesion. .
The Question That Remains Open
The study does not answer why undocumented population growth is associated with lower crime in some categories but higher robberies in others. Robberies going up while assaults and property crime go down is a puzzle that the researchers do not fully explain. This mixed finding suggests that the relationship between immigration and crime is not uniform across all types of offenses. It may be that different mechanisms are at work for different crimes, or that the data captures something about neighborhood dynamics that is not yet understood. .
Scalability is another open question. The study covers more than 100 cities, but the United States has thousands of municipalities. Whether these findings hold in smaller towns, rural areas, or cities with different economic profiles remains to be tested. The data also stops at 2018, so the years since then — including the pandemic period and its unusual crime patterns — are not covered. Future research will need to extend this analysis forward to see if the pattern persists. .
Sources
1. DOI: 10.1038/d41586-026-02542-0
2. Nature