What did the FAIR study show when it looked at SCAAP data
Executive summary
The Federation for American Immigration Reform (FAIR) analyzed State Criminal Alien Assistance Program (SCAAP) data and concluded that undocumented immigrants are incarcerated at substantially higher rates than U.S. citizens and lawful residents—reporting averages of roughly three times higher and as much as five times higher in some states [1] [2]. Independent analysts and think tanks have challenged FAIR’s methods and conclusions, arguing SCAAP is a flawed source for estimating comparative incarceration rates and that alternative analyses find lower or comparable incarceration rates for undocumented immigrants [3] [4] [5].
1. FAIR’s headline finding: illegal aliens incarcerated “three times” (and up to five times) more often
FAIR’s study of SCAAP reporting asserts that in states with large undocumented populations, SCAAP data indicate illegal aliens are incarcerated on average about three times as often as legal residents and citizens, and in some states the gap reaches as high as five-and-a-half times [1] [2]. FAIR emphasizes results for border and interior “preferred destination” states—singling out California where it reports undocumented people were about 3.3 times likelier to be incarcerated than legal residents—and frames SCAAP as the best available federal source because it documents convicted, deportable aliens who triggered SCAAP reimbursement [1] [6].
2. How FAIR used SCAAP: choice of numerator and denominator matters
FAIR’s approach relies on SCAAP counts of incarcerated noncitizens identified as potentially deportable (the program reimburses jurisdictions for incarcerating such individuals) combined with population estimates to produce incarceration-rate comparisons, a technique FAIR defends as “tested methods of statistical analysis” and suitable for the states analyzed [6] [2]. FAIR argues prior studies that showed lower undocumented crime rates omitted categories like drug and fraud offenses and therefore understate incarceration among undocumented people [1] [2].
3. Major methodological critiques: SCAAP is not a straightforward rate source
Critics from policy and research organizations counter that SCAAP cannot reliably produce incarceration-rate denominators because it reports reimbursable days and counts of identified aliens rather than a comprehensive flow or stock comparable to population estimates; FAIR’s use of end-of-year stock measures and private estimates for local jail populations is singled out as problematic [3]. Analysts note FAIR often fails to specify the exact years analyzed and mixes disparate datasets—issues that make replication and proper rate construction difficult [3].
4. Alternative analyses reach different conclusions using SCAAP or related data
Think tanks and researchers reanalyzing SCAAP data have produced opposite results in some cases: Cato and other analysts argue that when SCAAP is used with different assumptions and correct denominators, undocumented immigrants’ incarceration rates look lower or comparable to native-born Americans, and they point to state-specific reanalyses (e.g., Texas) showing undocumented shares of incarceration lower than their population share [4] [5]. FAIR has pushed back against those critiques, disputing claims about double-counting and timing lags in SCAAP reporting [7].
5. What the SCAAP program actually measures—and its limits for the debate
SCAAP is a federal reimbursement program that records costs and counts associated with incarcerating undocumented criminal aliens, and any jurisdiction that incurred reimbursable costs may apply for awards—making the dataset useful for tracking convicted, identified noncitizens but not designed as a national incarceration-rate registry [8]. Several reviewers therefore warn that SCAAP’s design, variable state reporting, timing lags from arrest to incarceration, and differences between local jail flows and state prison stocks complicate any straightforward inference about whether undocumented people “commit crime at a higher rate” nationwide [3] [4].
6. Bottom line: FAIR’s headline is supported by its methods but disputed on validity
FAIR’s plain conclusion—that SCAAP data in key states show undocumented people incarcerated at much higher rates—is accurate to FAIR’s reported calculations and is explicitly stated in their publications [1] [6]. However, independent critiques grounded in SCAAP’s structure and alternative denominator choices challenge the validity and replicability of that claim, meaning the debate rests largely on methodological framing—what SCAAP counts, how denominators are constructed, and which jurisdictions are included—which FAIR and its critics interpret differently [3] [4] [5].