Serious and violent crimes dropped more than forty percent during the 1990s, more than can be explained by demographic shifts. One reason for the crime drop has been the shrinking trade in crack cocaine, here is one account and a more detailed treatment. For whatever reasons, crack has turned out to be a one-generation drug. As crack fell in popularity, crime rates have fallen in turn.
Richard Rosenfeld, writing in the February Scientific American, raises but does not answer the question why crack markets have bred so much violence compared, say, to marijuana markets. I have thought of several possible and related hypotheses:
1. Cocaine supply, which requires processing in Colombia labs, is more centralized in nature. Centralization leads to monopoly profits and thus a greater incentive for violence to protect territory. There will be mobs and mafias at the top of the supply chain. They will feel threatened if anyone invades their turf, and the tendencies for violence work their way down to the retail level.
2. Marijuana is closer to a constant cost supply drug. You can always grow some in your backyard. The power of mobs is limited correspondingly and the incentive to invest in marketing and addicting your customers is weaker.
3. Marijuana is more of a depressant than is crack. Users are less likely to turn violent when deprived of the drug. Marijuana is less addictive in the sense of inducing total desperation.
4. Crack, which was essentially a new drug, required greater marketing than did marijuana. Marketing led to fights over turf and to violence.
5. Marijuana is used by many members of the middle and upper middle classes. Crack has been more popular in ghettos and with lower income groups, in part because it is potent and cheap. The reasons for the violence differential are found in the nature of the respective clienteles, rather than in the nature of the drugs per se. For instance, when drug carriers walk through a ghetto to supply their customers, they are at greater risk, more likely to carry a gun, more likely to meet with a gang, and so on.
Further ideas from readers are welcome.
The bottom line: When it comes to crime, it matters a great deal which drugs people are taking. Furthermore, if we are able to legalize some but not all drugs, we should consider legalizing the most objectionable drugs, not the tamest ones. Legalizing marijuana, whatever its merits and demerits, would not make a huge dent in the crime rate.
Addendum: Ed Lopez adds the following:
1. Crack is split up a lot more than marijuana so it has (had) far higher markup once it hit the street.
2. The early profiteers were the street distributors who discovered how to multiply the number of doses from the uncut cocaine. That gave suppliers higher up the chain something to grab at.
I think a lot of the violence question boils down to risk-takers competing for rents that weren’t protected by contract.
3. Crack is more ephemeral than pot and used with greater frequency, so users are more prone to commit crimes to acquire additioanl doses.