Proposition 47, which California voters passed by a large margin last month, converts simple drug possession from a felony to a misdemeanor. Opponents of the law maintain that the threat of a felony and the prison time that goes with it are necessary to pressure drug offenders into addiction treatment. This argument makes four assumptions, all of which I find questionable.

(1) Everyone who gets charged with drug possession needs addiction treatment. Epidemiologic data shows that the number of people who use drugs is substantially larger than the number of people who meet medical criteria for a substance use disorder. This means that the population of people who could be charged with simple drug possession includes many people who don’t have a disorder that an addiction treatment professional like me could treat.

Let me give you a concrete, real-world example: A noise complaint about a party results in a police officer discovering a group of freshman college students crushing and mixing Vicodin tablets into their beers. The tablets were purchased on line without a prescription and at the time of arrest half of dozen people in the room have them in their possession illegally and could therefore be charged. One of these young people has been a heavy drug user for years but of the others, a couple have only experimented with drugs a few times, a couple others are using drugs for the first time, and one has never used drugs at all, not even at the party that night: He is just holding one of the bottles as his friends use.

If you threaten all these people with a felony charge unless they enroll in drug addiction treatment, it could help the one with the established drug problem, but what about the others? They face a choice between a possible prison term or receiving treatment they don’t need. They will likely choose to take the unnecessary treatment, thereby wasting taxpayer dollars and taking a treatment slot away from someone who needs it.

(2) People who have drug problems and refuse treatment deserve prison sentences. Let’s say someone truly is addicted and the court gives them a choice between 30 months in prison or treatment. They might opt for treatment. But what if they say no? Is it fair to punish refusal to seek addiction treatment at the same level of severity that we might punish attempted rape? And is it worth over $100,000 to taxpayers to punish someone for refusing treatment?

(3) The only way to put pressure on people to enter treatment is with a felony charge and prison. Proposition 47 didn’t legalize drug possession. Offenders can still be charged with a misdemeanor and sentenced to up to a year in jail. There isn’t much evidence that people with drug problems think far ahead such that the prospect of a 30 month prison sentence motivates them more than the prospect of a 6 or 12 month jail sentence.

(4) The only options for substance-involved offenders are prison or treatment. A new generation of swift, certain and fair supervision programs allow offenders to stay in the community while reducing their substance use, decreasing their risk of committing more crimes and lowering their likelihood of going to prison. Some offenders require concurrent addiction treatment to change but many of them do not: Faced with regular alcohol/drug testing and a transparent and fair set of immediate consequences (e.g., a night in jail if they drink or use drugs) many offenders change their behavior. The passage of Proposition 47 is a great opportunity for more California judges and probation departments to begin implementing these innovative supervision programs.