The motivational- and opportunity-effects of unemployment rates on Japanese juveniles' homicide rates

Abstract

Based on Cantor & Land (1985)'s theory (C-L theory) and Greenberg (2001) and Yuma (2009)'s statistical model (G-Y model), this study examined the effects of the motivational-effect (measured by the first difference of unemployment rates (UR)) and the opportunity-effect (measured by original series of UR) on original series of Japanese juveniles' homicide rates (HR), using one-year-interval time-series data (1974–2006). Cointegration regressions revealed long-run equilibrium relationships between original series of HR and original series of UR both in a 16–17 years old group and in a 18–19 years old group. UR had significant and increasing effects on HR in the long-term. Error correction models also showed that in the short-term, effects of UR were significant and positive on HR in both groups. Derived from these results, G-Y models found that opportunity-effects of UR on original series of HR were significant and positive in the groups, which was opposite to C-L theory. The models also found that a motivational-effect of UR on original series of HR was significant only in the 18–19 years old group as predicted. The results were discussed in regard to (a) the differences between situations in which Japanese juveniles' homicide occurred and those in the United States, and (b) the time-lag of the motivational-effect.