From a paper by Alonso-Borrego, Garoupa, and Vázquez, "Does Immigration Cause Crime? Evidence from Spain" (American Law and Economics Review, Spring 2012). The draft is here.
The present work introduces a first comprehensive analysis of the relationship between immigration and crime in Spain. In the context of the EU, Spain is not a country with high crime rates. During the last decade of significant immigration, Spain has seen an important rise in crime at a similar pace with its immigrant population, but to a lower rate than other countries. We hypothesize that the explanation of this behavior is related to the individual characteristics of the immigrants that Spain has received. We argue that it is not so much the number of immigrants but the specific characteristics that seem to explain the relationship between crime and immigration in Spain.
In this respect, cultural proximity and education must be specially noted. Immigrants from some populous groups, such as those who are Spanish native speaking, present a substantial proportion of people with at least secondary education, for whom criminality is much lower. This effect has contributed decisively to avoid any kind of explosion of criminality. Gender has also positively contributed to this effect. In fact, even after controlling by gender and education, we can still conclude that Latin American immigration has probably undermined the potential rise of criminal rates in Spain. This result also happens, to a lesser extent, with EU15 immigrants. Our result is fully consistent with the evidence for the United States regarding Mexican immigrants (known as the Latino Paradox), where immigration from Mexico has lowered crime rates in some areas.
Other immigrant groups with lower education levels have contributed significantly to the rise in crime rates. It must also be noted that these immigrants started at arrival with a crime rate significantly higher than Spanish nationals, but have been converging as their size and composition changed. It must be noted the specific case of the Romanian immigrant group, now one the most numerous in Spain. Even though it started with high crime rates, nowadays it presents lower rates than nationals in the twenty-fifty age group.
This work also provides for a good example of standard discussions in the econometrics of crime. We have observed how the booming stage of the business cycle in Spain reduced crime because it increased the opportunity cost; we have seen that population density favors crime because it makes harder the identification and tracking of criminals; we have concluded that crime is concentrated among young males and lesser-educated individuals. The implications of this work for designing public policies are clear. Immigration is not a simple homogeneous phenomenon and must not be treated as such. Public authorities should respond with differentiated policies, depending on the relevant characteristics.The possible costs of immigration should be judged along with the many benefits, such as innovation and entrepreneurship, which are huge, and very possibly outweighs the costs by far. Contrast the paper above with this one by Reid et al., (2005).