The Age Structure-Crime Rate Relationship: Solving a Long-Standing Puzzle

Objectives Develop the concept of differential institutional engagement and test its ability to explain discrepant findings regarding the relationship between the age structure and homicide rates across ecological studies of crime. We hypothesize that differential degrees of institutional engagement—youths with ties to mainstream social institutions such as school, work or the military on one end of the spectrum and youths without such bonds on the other end—account for the direction of the relationship between homicide rates and age structure (high crime prone ages, such as 15-29). Methods Cross sectional, Ordinary Least Squares regression analyses using robust standard errors are conducted using large samples of cities characterized by varying degrees of youths' differential institutional engagement for the years 1980, 1990 and 2000. The concept is operationalized with the percent of the population enrolled in college and the percent of 16-19 year olds who are simultaneously not enrolled in school, not in the labor market (not in the labor force or unemployed), and not in the military. Results Consistent and invariant results emerged. Positive effects of age structure on homicide rates are found in cities that have high percentages of disengaged youth and negative effects are found among cities characterized with high percentages of youth participating in mainstream social institutions.