The increase in immigration enforcement during the past two decades has led to a larger number of immigrants being detained in the U.S. criminal justice system. Using data from the 2006–2018 Annual Survey of Jails, we examine the impact of immigrants being held for Immigration and Customs Enforcement (ICE) on the conditions in U.S. jails. We find that increases in the number of detainees held for ICE are related to higher noncitizen jailed populations that are not offset by reductions in their citizen counterparts, likely contributing to worse confinement conditions. This is reflected in the higher levels of overcrowding and understaffing, as well as in the longer stays in jail and more physical assaults associated with a larger number of ICE detainees. These findings prove robust to using data on two local interior immigration enforcement programs responsible for the growing number of immigrant detainees in local jails—287(g) agreements and Secure Communities—as instruments to address the endogeneity of the number of ICE detainees with respect to jail conditions. The results are driven by slightly over half of U.S. counties located either along the United States–Mexico border or in states with a large or fast-growing immigrant population.

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移民政策、移民拘留和美国监狱系统

过去二十年来移民执法的增加导致更多的移民被美国刑事司法系统拘留。使用 2006-2018 年监狱年度调查的数据，我们研究了因移民和海关执法 (ICE) 而被关押的移民对美国监狱条件的影响。我们发现，被 ICE 拘留的人数增加与非公民入狱人数增加有关，而这些人数并未被公民同行人数的减少所抵消，这可能导致监禁条件恶化。这反映在更高水平的过度拥挤和人手不足，以及与更多 ICE 被拘留者相关的更长时间的监狱停留和更多的人身攻击。这些研究结果证明，使用两个地方内部移民执法计划的数据是可靠的，这些计划负责在当地监狱中不断增加的移民被拘留者数量——287(g) 协议和安全社区——作为解决 ICE 被拘留者数量的内生性的工具监狱条件。这一结果是由略超过一半的美国县推动的，这些县要么位于美墨边境，要么位于移民人口众多或快速增长的州。