What major studies (e.g., 2018 CATO, 2019 Stanford) found about immigrant crime rates vs natives?
Executive summary
Multiple major studies converge on the finding that immigrants—both legal and undocumented in many analyses—have lower rates of incarceration, arrest, and many measured felony offenses than U.S.-born Americans, with high-profile work from Stanford, state-level Texas analyses published in PNAS and by the National Institute of Justice, and repeated Cato Institute briefs all reporting sizable gaps in favor of lower immigrant criminality [1] [2] [3] [4].
1. The long-run Stanford finding: immigrants far less likely to be incarcerated
A multi-university team led by Stanford economist Ran Abramitzky analyzed historical and contemporary incarceration data and concluded that immigrants have not been more incarcerated than the U.S.-born over the last 150 years and that, in recent decades, immigrants are about 60% less likely to be incarcerated than U.S.-born individuals—a headline result emphasized in reporting and Stanford’s own writeups [1] [5] [6] [7].
2. Texas as a microcosm: PNAS and NIJ studies showing lower offending among undocumented immigrants
Highly granular arrest data from the Texas Department of Public Safety underpin a 2020 PNAS study which found undocumented immigrants had substantially lower felony arrest rates than native-born citizens and also lower rates than legal immigrants across multiple offense categories for 2012–2018 [2] [8]. The National Institute of Justice–supported analyses reach similar conclusions, reporting undocumented offenders had the lowest homicide and overall arrest rates in the study period and were, for key offenses, well below U.S.-born rates [3] [9].
3. Cato Institute’s series: lower arrest/conviction rates but contested methodology and political context
Cato’s reports—cited by other researchers and updated over multiple years—have generally found illegal immigrants in Texas and nationwide to have lower conviction and arrest rates than the native born (for example, a 2019/2021 brief reporting illegal immigrants were roughly 37% less likely to be convicted than native-born Americans in Texas) but Cato’s work has spurred rebuttals and methodological critiques [4] [8]. Scholars who reanalyzed Texas data argue that some earlier Cato approaches undercounted legal immigrant arrests or misclassified individuals, showing how data source choices materially affect results [8] [2].
4. Cross-study consistency and the patterns by crime type
Across multiple institutional sources—including migration-policy syntheses and state studies—immigrants are reported as having substantially lower rates of weapons, violent, property, and drug incarcerations in many comparisons: for example, migration-policy reporting summarizes findings that U.S.-born citizens were far more likely to be incarcerated for weapons and violent offenses and often more than twice as likely for property or drug crimes [10]. The Texas analyses and PNAS paper repeatedly underscore that undocumented immigrants’ offending rates were lower for violent, property, and drug felonies [2] [3].
5. Why researchers warn about caveats: measurement, classification, selection, and agendas
Researchers uniformly caution that measuring “criminality” is fraught: incarceration and arrest rates are imperfect proxies for actual offending; datasets vary in how they record immigration status leading to misclassification (scholars argue Cato’s reliance on DHS data may have undercounted legal immigrant arrests), and selection effects (who migrates) and enforcement differences (immigration prosecutions or differential sentencing) can bias simple comparisons—points emphasized in the PNAS, NBER/Stanford working papers, and critiques of the Cato briefs [8] [7] [11]. Additionally, think-tank affiliations color framing—Cato’s libertarian stance and advocacy groups’ syntheses each have implicit agendas that shape emphasis and policy prescriptions even when reporting similar empirical patterns [4] [10].
6. Bottom line: consensus with nuance
The broad academic and empirical pattern across major studies is clear: immigrants as a group—including many analyses of undocumented populations—tend to have lower arrest, conviction, and incarceration rates than native-born Americans, often substantially so (Stanford’s 60% incarceration gap and Texas studies’ large differentials are flagship examples) [1] [2] [3]. Yet the literature also stresses important methodological limits, different data choices that can change magnitudes, and the political uses of these findings—so the consensus is strong on direction but nuanced on the exact size and interpretation of the gap [8] [11] [4].