Is Cannabis a Stepping-Stone for Cocaine?

This Paper uses a unique dataset collected among inhabitants of Amsterdam, to study the dynamics in the consumption of cannabis and cocaine. If people start using these drugs they are most likely to do so at age 18-20 for cannabis and age 20-25 for cocaine. An analysis of the starting rates shows some evidence of cannabis being a ‘stepping stone’ for cocaine. The fact that some individuals use both cannabis and cocaine has, however, to do mostly with (unobserved) personal characteristics and not with the use of cannabis causing the use of cocaine.