"Marijuana use is roughly equal among Blacks and whites, yet Blacks are 3.73 times as likely to be arrested for marijuana possession."
This is the statistic you're referencing.
The claim that Blacks and Whites use drugs at roughly equal rates is based on self-reporting. There is a serious problem with this: Blacks are more likely than Whites to lie about using drugs. How do we know? Well, criminologists sometimes conduct studies in which they run biological tests on people’s hair, blood, urine, etc., to test what drugs they have recently taken and then compare that to what drugs they claim they have recently taken. Such studies consistently find that Blacks are more likely than Whites to lie and claim that they have not used a drug that they really have used (Page et al. 2009, Falk et al. 1992, Feucht, Stephens, and Walker, 1994, and Fedrich and Johnson 2005). In fact, as reviewed in Ellis, Beaver, and Wright's Handbook of Crime Correlates, most studies based on self-reported criminal history suggest that Blacks are not more likely than Whites to commit crime in general. And, as will be seen below, that is certainly false.
Moreover, Blacks do lots of stupid shit, compared to White drug users, that makes them more likely to be arrested. To quote one study comparing Black and White drug users: “African Americans are nearly twice as likely to buy outdoors (0.31 versus 0.14), three times more likely to buy from a stranger (0.30 versus 0.09), and significantly more likely to buy away from their homes (0.61 versus 0.48).” (Ramchand , Pacula, and Iguchi MY 2006). Similarly, a report issued by the Justice Department found that Black drug users use drugs more often than White drug users, use more dangerous drugs than White drug users, and are more likely to use drugs in areas with high crime rates (Lagan 1995). All 6 of these differences will make Black drug users more likely to get arrested than White drug users. Given all this, there is no good reason to suppose that Black drug arrest rates reflect racism. It is far more likely that they reflect Black drug users' dishonesty as well as the reckless manner in which they use drugs.
