The Volokh Conspiracy

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Study Finds Sanctuary City Policies Reduce Deportations Without Increasing Crime

The much-publicized result is ocnsistent with previous studies on the impact of sanctuary city


Over the last decade or so, many state and local governments have adopted "sanctuary" policies that restrict their law enforcement agencies' cooperation with federal efforts to deport undocumented immigrants. Critics, including the Trump administration, claim that sanctuary policies increase crime. Trump has adopted a range of policies designed to coerce sanctuary jurisdictions into doing the bidding ICE, which in turn has led to numerous court decisions striking down the administration's policies.

A recent widely publicized study by Stanford University political science research fellow David Hausman finds that sanctuary city policies result in a reduction in deportations, but no accompanying increase in crime. Here is the abstract summarizing the findings:

The US government maintains that local sanctuary policies prevent deportations of violent criminals and increase crime. This report tests those claims by combining Immigration and Customs Enforcement (ICE) deportation data and Federal Bureau of Investigation (FBI) crime data with data on the implementation dates of sanctuary policies between 2010 and 2015. Sanctuary policies reduced deportations of people who were fingerprinted by states or counties by about one-third. Those policies also changed the composition of deportations, reducing deportations of people with no criminal convictions by half—without affecting deportations of people with violent convictions. Sanctuary policies also had no detectable effect on crime rates. These findings suggest that sanctuary policies, although effective at reducing deportations, do not threaten public safety.

The article is, unfortunately, gated, so it may not be easy for readers without university or research institute affiliations to get free access. But this Washington Post article has a good summary of the results,as does the Hill. Hausman's findings are consistent with those of previous academic research on the subject, which consistently also concludes that sanctuary city policies do not result in increased crime rates, and may even reduce them. In Chapter 6 of my recent book, Free to Move, I use this and related evidence to make the point that we can better combat violent and property crime by redirecting resources currently used for deportation efforts to conventional policing. For example, I estimate that  zeroing out ICE immigration enforcement programs would free up enough funds to pay the salaries of over 60,000 new police officers. And unlike ICE's current activities, extensive evidence indicates that having more conventional cops on the street really does reduce crime—though it is also important to do more to curb police abuses against civilians, including racial profiling.

I do not suggest that hiring more cops is the best possible use of resources currently devoted to deportation efforts. But, if the goal is reducing crime rates—particularly when it comes to violent and property crimes that actually harm people, it would be a major improvement over the status quo.