Cocaine powder was usually sold in quantities of multiple doses, whereas crack was much more often purchased one dose at a time. This led to a dramatic increase in the number of transactions, which required many more sellers, which helped lead to the recruitment of kids as sellers. Increasing the penalties for adult crack sellers also encouraged sellers to recruit kids to sell drugs for them. Kids have little sense of risk, or concern about arrest or imprisonment. In the drug market the dealers have to carry guns to protect themselves from being robbed, and so the kids recruited also carried guns.
Kids are highly networked, compared to adults.
They are extremely concentrated, going to the same schools, belonging to the same kinds of clubs, and hanging out in the same streets. The practice of carrying guns for protection or for status, rapidly diffused among the non-drug selling kids. Kids have always fought with each other. But now guns have replaced fists. In attempting to deter drug selling, we are near the limit in the sanctions we can threaten.