By Benjamin Gonzalez-O’Brien (San Diego State University), Loren Collingwood (University of California at Riverside), and Stephen El-Khatib (University of California at Riverside)
The July 1st, 2015 shooting of Kathryn Steinle in San Francisco by Juan Francisco Lopez-Sanchez, an undocumented immigrant, reignited the debate over sanctuary policies in the United States. Lopez-Sanchez had been deported seven times and had been arrested on a marijuana possession charge in San Francisco, but was subsequently released when the city chose not to prosecute him despite a request by Immigration and Customs Enforcement (ICE) that he be held so he could be taken into custody for deportation. Then Republican presidential candidate Donald Trump seized on the shooting as an example of the crime encouraged by sanctuary city policies throughout the United States and promised to strip funding from these localities if he became president. As president, Trump followed through with this promise, signing an executive order titled, “Enhancing Public Safety in the Interior of the United States,” on January 25th, 2017, just days after his inauguration.
Yet it remains unclear whether sanctuary policies lead to increases in crime as there have only been a handful of studies to date examining this question. In 2013, Lyons et al. (2013) found that those cities with sanctuary policies had lower robbery and homicide rates in neighborhoods with high concentrations of immigrants, suggesting that sanctuary policies are associated with lower crime rates. Similarly, Wong (2017) found that when sanctuary and non-sanctuary counties were compared using a matching technique, counties with sanctuary policies had lower crime rates than similar non-sanctuary counties. Our study builds on these findings by analyzing the effects of sanctuary policies on different types of crime while also matching cities based on variables like population, the size of the Latino community, economic criteria, and other racial criteria. We define a sanctuary city as a city or police department that has passed a resolution or ordinance expressly forbidding city or law enforcement officials from inquiring into immigration status and/or cooperation with ICE and base our list on data provided by the National Immigration Law Center (NILC). All sanctuary cities included in the study passed sanctuary policies during or after 2002.
We conducted two types of analyses to examine the relationship between sanctuary city policies and crime. The first is a simple difference of means t-test at the individual sanctuary-city level. Taking crime data from all 55 cities in our dataset that passed sanctuary city laws post 9/11, we compare the crime rate in the year following implementation of a sanctuary policy to the crime rate in the year preceding its implementation. In the second analysis, we employ a matching causal inference strategy to test the claim that sanctuary cities are associated with more crime than are non-sanctuary cities. This approach lets us control for – and thereby rule out – a variety of confounding factors that might lead to the making of a sanctuary city in the first place.
We found no statistically significant difference in crime rates for violent crime, property crime, or rape in a city after the passage of a sanctuary policy. Figure 1 demonstrates this for violent crime, showing that while some cities saw an increase in crime following passage, others saw a decrease or no change. Figure 2 compares violent crime rates in matched sanctuary and non-sanctuary cities to see if this differs between cities based on sanctuary status.
We found no relationship between sanctuary status and crime rates. While Figure 2 presents the findings for violent crime, this held for property crime and rape as well. Violent crime was slightly higher in sanctuary cities than non-sanctuary cities, but judging by the error bands — which capture the uncertainty underlying these estimates — the relationship is not statistically significant before or after a sanctuary policy is passed.
Based on our findings we can confidently state that sanctuary city policies do not increase crime rates, despite the claims made by the Trump administration. Comparing the crime rate in each city prior to and in the year following the passage of a sanctuary policy shows there is no relationship between the two. Furthermore, when sanctuary cities are compared to non-sanctuary cities after matching across a number of criteria to ensure similar cities are being compared, there is also no relationship to be found between crime and sanctuary status. Immigrants, both documented and undocumented, have long been the target of rhetoric claiming they are more inclined towards criminality, despite significant evidence to the contrary, and the argument that sanctuary cities “breed crime” seems to be another example of fear-mongering with little respect to the facts. Our findings will hopefully help to move the sanctuary debate in a positive direction where the policies can be assessed based on their costs and benefits rather than on unfounded claims that have ugly historical echoes.
Benjamin Gonzalez-O’Brien is an assistant professor of political science at San Diego State University whose research interests include American politics, immigration policy, racial and ethnic politics and American political development.
Loren Collingwood is an assistant professor of political science at University of California at Riverside whose research interests include American politics, political behavior, and race and ethnic politics.
Stephen El-Khatib is a doctoral student researcher at University of California at Riverside whose research interests include political conflict, immigration, and race and ethnic politics.
Check out this previously published post about The Politics of Refuge: Sanctuary Cities, Crime, and the Collected Works of Jefferson Beauregard Sessions III