University of Southern California: Data study uncovers inequities in U.S. naturalization adjudication process

It took filing a federal lawsuit for Professor Emily Ryo to complete a new empirical study on the naturalization, or citizenship, process.

“The Importance of Race, Gender, and Religion in Naturalization Adjudication in the United States,” co-written with Reed Humphrey (MPP 2018), Ph.D. candidate at the Evans School of Public Policy, University of Washington, indicates that naturalization adjudication outcomes are significantly different for many racial, ethnic, religious and gender groups.


Professor Emily Ryo’s new research indicates persistent disparities in naturalization adjudication outcomes.The research, posted in late February in the Proceedings of the National Academy of Sciences (PNAS), determined that, despite widespread assumptions of fair and equitable treatment in the process, race, ethnicity, gender and religion predict approval rates. The study shows probability of approval for Black males at 89 % compared to 94 % for White females; probability for Blacks from Muslim-majority countries is 86% compared to 96% for Whites from non-Muslim majority countries; and probability for females from Muslim-majority countries was 87%, compared to 93% for females from non-Muslim majority countries. The data range from the years 2014-2018.

“U.S. citizenship laws have a long history of formally excluding non-whites, religious minorities, and females,” she said. “We assume all that is in the past, because [our] laws now prohibit those kinds of discrimination. We shouldn’t expect to find continued disparities by race, gender, and religion. So the persistent disparities that we found are surprising and troubling.”

Ryo, who studies immigration enforcement, filed requests under the Freedom of Information Act (FOIA) for data on naturalization applications with the United States Citizenship and Immigration Services (USCIS) in August of 2018. But when officials were slow to cooperate with her requests, in July 2020 she filed federal lawsuit against USCIS, represented by American Oversight, a nonpartisan government watchdog agency in Washington, D.C. The litigation took more than a year.

“I was shocked to find USCIS has never released individual level data on their naturalization decisions,” she said. “That meant no one could address basic and important questions like whether certain groups are more likely to be denied, and whether denial rates depend on which field office adjudicates the application. The only way to obtain the data to answer those kinds of questions was to file a FOIA.”

Data on naturalization application denials missing or obscure

Ryo’s inquiries revealed that, despite laws requiring USCIS to explain the basis for denying applications, 20 % of denials in the data were simply missing. Another 14 % were attributed to reasons such as “Other” and “Secondary Evidence” that are never explained. The study highlights the need for understanding the possible role of bias in agency decision-making and how structural inequities in the criminal justice system that disproportionately impact certain immigrant groups might become compounded in the immigration adjudication system, Ryo says.

In a companion study that Ryo and Humphrey plan to publish separately, they also completed an analysis of disparities in outcomes from different field offices throughout the United States.

Ryo hopes the PNAS study helps to illuminate the full consequences of disparities on individuals and families trying to gain rights as U.S. citizens.

“My hope is that this study brings to light the type and nature of inequalities that characterize the naturalization system so that we can develop a system that is more fair and equitable,” she said.