Law: a tax on free speech?

a thought came up as a combination of the con law and the regulation classes that i'm taking: wouldn't it be cool to replace the MPAA's movie rating system with a simple tax on movie violence and obscenity and other undesirable behavior? for instance, smoking in movies and TV encourages teens to smoke in emulation.

for the argument to work, we need to assume that negative TV messages have social externalities. that is, while they may increase a film's sales, they adversely affect public morals.

the current system, to me, has a serious incentive problem. there are four grades of films: G, PG, PG-13, and R. (we'll leave aside M). each of those four ratings has a fair amount of room for maneuver. the rules are fairly reasonable, but by only having four categories, there is inherently a problem that most movie producers will not adjust the content of the films unless the film falls close to the boundary between two ratings.

For instance, if a film uses the F-word 1-3 times, it gets a PG-13. So there is an incentive to lower the usage of the word if there's only 4 instances of it. But, if the character says it more than 3 times, then there is no incentive to cut back. the character can say it 10 times, 20 times, and still keep the same rating. (although the reviewer's discretion may jump in at a certain point).

a similar problem exists that violence usually gets a free pass, whereas sex is heavily censored. and because it goes on behind the scenes, the public doesn't have a good idea of the relative weights of these screen acts.

in contrast, a tax system to obscenity would make film makers internalize the costs of obscenity (with proceeds going to, say, PBS). a filmmaker would have to make a cost-benefit decision on whether each instance of nudity or of violence is worth - artistically speaking - the tax penalities he would have to make for it.

So a system where every instance of the F-word is taxed at (arbitrarily speaking) 0.5% of revenue, filmmakers would limit that word only to those instances where it adds to the storyline. extraneous smoking, sex, and shooting scenes would be taken out, reducing the overall amount of violence while giving the artist the maximum flexibility to preserve the storyline.

is this censorship? well, i want to draw a distinction between movies as commodity and movies as expression. no, it's not a clear line. but one can certainly argue that nowadays, movies are as much a cultural product (along the thinking of the Frankfurt School), made for mass consumption, as they are mediums for expression. to the extent that they exist to make their producers rich, there is not a strong justification to protect them absolutely. and to the extent that the tax system can deter egregious behavior, perhaps it may forestall legislative backlashes that are more restrictive, just as what was proposed in the aftermath of the columbine shootings.