[lazide]

Interestingly enough - all crime (including in the US with it's war on drugs) has dropped dramatically since the 80's. Lots of theories about leaded gasoline phase-outs, etc. but it's a complex multi-variate problem. Merely having the issues about use widely known (and the initial round of people super susceptible to it) can also cause many people to shy away, with significant decreases in abuse.

[the-dude]

Dutch coffeeshops keep large amounts of people away from 'regular' drugs dealers who carry coke/heroin besides weed.

Economic tide : the 80ies was a different time with lots of youth unemployment in NL/NWE.