The ever interesting Michael at 2Blowhards had the following post on the history of porn in Denmark:
Porn was legalized in two stages. The first, in 1967, lifted restrictions on print porn ("print" as in "text" -- novels, etc). The second stage ended restrictions on virtually all other kinds of porn.
While the business of erotic novels and such had flourished under censorship in a modest and illicit way, once this work was made legal everyone lost interest in it. The market for it collapsed.
Legislators took the second step -- making all other kinds of porn legal -- believing that the demise of text-porn was a trustworthy predictor of the move's consequences. Instead, demand for all these other kinds of porn (pictures, movies, etc) exploded.
Unsure what to make of this but ever-curious.
My take: I think one needs to look at a much broader level as well. Enacting a law is the typical default response from lawyers and politicians when they see a vice. But for laws to be effective there probably needs to be a social will to enforce those laws. To quote a great sociologist Emile Durkheim, �When mores are sufficient, laws are unnecessary. When mores are insufficient, laws are unenforceable.� By hurrying to enact laws, we are also taking away responsible behavior as well.
