toward this century's end. We focus on issues of immigration and crime during these third and fourth waves. These periods are sufficiently different and far apart in time that it is necessary to relearn and rethink much of what was once taken for granted about this topic. This task is made more difficult by the fact that, in between the last two periods of concern about immigration and crime, many criminal justice agencies stopped recording information about the presumed immigration and citizenship status of offenders. It is therefore necessary to piece together information about our topic from a patchwork of sources. As we note, the depth and detail of the data sources we must draw from are uneven and uncertain. The results of our work suggest that some of the public concern about immigration and crime may be overdrawn; however, the nature of the data problems also limits the certainty with which conclusions can be drawn in this field.
Undoubtedly the most salient questions involve the issue of whether immigration increases crime. Of course, in an absolute sense, it probably does. Immigration brings more people into the country, and unless this process is counterbalanced by emigration, the absolute volume of crime will very likely increase. In addition, immigrants are often disproportionately male and at early ages of labor market entry and advancement. Because young males are disproportionately likely to be involved in crime in all parts of the world that we know about (Hirschi and Gottfredson, 1983), this may also contribute to increases in crime. If our concern is solely to reduce crime, it simply does not make sense to encourage young males to immigrate in large numbers. However, because we also value the labor of young male immigrants, and indeed often rely on this labor in the context of shortages of particular kinds of workers, questions about contributions of immigration to crime are more likely to be relative than absolute. In this sense we will probably want to know whether immigrants who enter the country contribute to crime beyond what we could otherwise expect of citizens of similar numbers, ages, gender, and so on.
A further complication in assessing the involvement of immigrants in crime is that immigrants may not be treated the same as citizens in the criminal justice system. If immigrants are more or less vulnerable than citizens to arrest, detention, conviction, and imprisonment, their representation in official crime statistics may be correspondingly biased. This problem as well must be addressed in assessing the relationship between immigration and crime. These difficulties help to explain why questions about immigration and crime have recurred over the past century in the United States. We first review the historical background of these concerns and then turn to contemporary developments in reaching tentative conclusions about immigration and crime.
The close of the Past century brought concerns about immigration and crime that persisted for several decades. These concerns were associated with a third