Why have robberies become less frequent but more violent?
Although the incidence of robbery has declined sharply since the early 1990s, the proportion of robberies resulting in victim injury has increased and the rate of victim resistance has remained relatively stable. We provide a theoretical explanation for these trends. Deterrence policies that make robbery more costly for offenders result in a decline in the incidence of robbery through the exit of those with the best outside options. The group of robbers who exit consists disproportionately of those who would have fled in the face of victim resistance, and hence, the pool of remaining robbers is more likely to respond violently to noncompliance by victims. This effect is reinforced by what we call victim hardening: a change in the distribution of attributes in the victim pool that makes resistance more likely. This can arise, for instance, through an increase in crime avoidance by the most compliant victims. Deterrence and victim hardening both result in lower robbery rates and greater violence conditional on resistance but have opposing effects on the rate of resistance, thus accounting for its relative stability over time.
Source: “Why Have Robberies Become Less Frequent but More Violent?” from Journal of Law, Economics, and Organization