Immigration and Crime in the U.S.

Measuring migration and crime

U.S. authorities do not track where migrants live. However, the Transactional Records Access Center (TRAC) at Syracuse University used the Freedom of Information Act to obtain over 9 million records of deportation proceedings over the last decade. The TRAC data identifies 415 U.S. counties with 1,000 or more migrants who faced or are facing deportation because they were denied asylum, overstayed visas, or entered the country illegally and came to the attention of local authorities.

We use the TRAC data to identify communities with high migrant populations (link). While the number of deportation cases does not tell exactly how many migrants live in a community (whether legally or illegally), it is a good indicator of migration’s impact and the general movement of migrants throughout the country.

Our data on crime rates comes from the Major Cities Chiefs Association (MCCA), which annually reports the number of major crimes (homicide, rape, robbery, and aggravated assault) for 63 high-population communities in the U.S. and Canada. Across these communities, the individuals from the TRAC data vary from .53% in Honolulu, Hawaii, to 12.9% in Miami, Florida.

The MCCA data only includes crimes that are reported to the police and does not include misdemeanor offenses. However, in comparison to FBI data (the other main source), it is available at the community level, which is what we are analyzing here.

What does the data show?

In most of the communities in the MCCA data, major crime rates dropped substantially between 2019 and 2023. The average decline is -44.2%. There is considerable variation: crime in Philadelphia saw the largest decline at 73.2%, while crime in Oklahoma City increased 54.4%. The question is, across the 63 communities, are higher migrant populations associated with changes in crime rates?

The figure below shows the relationship between a community’s deportation cases (measured as a percentage of total population) and the percentage decline in major crimes between 2019 and 2023.

The figure shows no distinct relationship between the size of a community’s deportation cases and the decline in crime – the dotted trend line is essentially flat.

In concrete terms, Milwaukee and Miami saw almost the same decline in crime (-42.9% for Milwaukee and -41.2% for Miami), even though Milwaukee has fewer deportation cases than Miami (1.2% vs 12.9%). Similarly, Oklahoma City and Philadelphia have similar deportation cases (3.6% vs. 2.2%), but major crimes increased over 50 percent in Oklahoma City and declined over 75 percent in Philadelphia.

This analysis is not the last word. It may be that crime rates in smaller communities are more sensitive to the size of the migrant population. The brief linked earlier identified communities where deportation cases are a relatively high percentage of total population. Another possibility is that migration is related to certain crimes such as auto theft or carjacking.  We will consider both topics in future briefs.

The Take-Away

In almost all of the large U.S. cities analyzed here, major crimes decreased substantially between 2019 and 2023.

The size of the migrant population in these cities varies tremendously.

In these communities, there is no relationship between the reduction in major crime and the size of the migrant population.

Future work should examine the impact of migrants on non-major crimes such as auto theft and other types of criminal offenses in smaller communities.