– http://yglesias.thinkprogress.org/2010/10/coffee-shop-crackd...
the main market for the coffee shops turns out to be drug
tourists from abroad
That's not true. Although a number of coffee shops in Amsterdam and in cities close to the borders with Germany and Belgium primarily sell to tourists, there are many more coffeeshops that just sell to the local users.Just a note of caution - while looking at what other places do definitely brings information to the table, you can't always say "if place A does X, doing X in place B will make it like place A".
The classic example of this is alcohol. Alcoholic beverages are not prohibited, but if you walk through an Italian town center at 11pm on a Friday night you won't see the scenes of public drunkeness and alcohol-fueled disorder that you see, say, in an English town center at the same time.
While I don't necessarily disagree with the larger point, in these kinds of policy area there is a level of unpredictability as to what will happen when a previously controlled substance is legalised, because patterns of consumption are convolved with local social norms.