Risk Assessment as Policy in Immigration Detention Decisions

A large literature examines the effects of algorithmic risk assessments on judges’ bail decisions in criminal cases. This article examines these effects in the immigration detention context. In 2017, US Immigration and Customs Enforcement changed its risk-assessment tool. Before the change, the tool could recommend detention, release, or referral to a supervisor; afterward, it did not recommend release—ever.

Taking advantage of the suddenness of this change, I show that the removal of the release recommendation reduced actual release decisions by about half, from around 10 percent to around 5 percent of all decisions. Officers continued to follow the tool’s detention recommendations at only a slightly lower rate after the change, and when officers did deviate from the tool’s recommendation to order release, supervisors became more likely to overrule their decisions.