Marijuana legalization and drug abuse as a cause for entry into foster care

In recent years, many states have legalized marijuana for medical use, recreational use, or both. At the same time, parental drug abuse is now the second most frequent reason for a child’s placement into the foster care system. We investigate the causal link between these two facts. Do states that legalize marijuana use experience an increase in foster care entries related to drug abuse? We utilize multiple difference-in-difference approaches to exploit the state level variation in recreational and medical marijuana laws. Our findings suggest that when states permitted recreational marijuana use, there was no corresponding change in the number of foster care entries related to drug abuse, relative to control states. For the legalization of medical marijuana, we find a roughly 20 percent decrease in the number of cases associated with parental drug abuse in the second year after legalization, followed by a roughly 30 percent decrease in the third and fourth years. We isolate this effect as coming from states with relatively strict tetrahydrocannabinol limits. While we find fewer entries related to parental drug abuse, there is no convincing evidence that total removals decreased.