Crime and the Mariel Boatlift

Our paper describes crime effects 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 strong evidence the phenomenon comparatively increased property crime and murder rates; we also document weaker but suggestive relative growth in per capita violent crime linked with the influx of Cubans. Compositional features of the newcomers seemingly drive our results; the disproportionately young, male Mariel Cubans’ characteristics highly correlate with illicit activity. Given the unique composition of the group and the absence of rigorous screening, our findings likely constitute the “upper bound” of crime caused by migration.