Crime and the Mariel Boatlift

We describe crime attributable to the Mariel Boatlift, the 1980 Cuban refugee crisis that increased Miami’s population by nearly 10%. Using synthetic control methods to match Miami with cities that exhibit similar pre-intervention crime patterns, we find the phenomenon comparatively increased property crime and murder rates; we also document weaker but suggestive relative growth in violent crime. Compositional features of the newcomers partially drive results; the disproportionately young, male Cubans’ characteristics highly correlate with illicit activity. However, the degree of prior incarceration and psychiatric institutionalization likely explains the majority of the observed effects. Given the group’s unique composition and the absence of rigorous screening, it likely constitutes the worst observed migration event in terms of public safety in US history. The Marielitos bear little resemblance to other groups of newcomers. Hence, it would be imprudent to use crime connected with the 1980 event we study to inform immigration policy.