Using the relatively mild "Playboy" as a proxy for hardcore pornography seems a bit strange.

However, I believe your main point holds, for the following reason. I assume that mass access to the Internet has largely increased access to porn (to a first approximation, the Internet is essentially a porn distribution channel). So if porn leads to rape, we should expect an increase in rape rates (all other things being equal) in recent years.

However, not only do rates remain stable/downward, but the trend also doesn't differ significantly from other crime rates - such as murder rates, as indicated by the same website you linked to. This suggests that mass access to all kinds (an I really mean all kinds) of pornography has not had a large effect on aggregate rape rates, so far.

Of course, the effects of an entire generation of frustrated nerds being raised on 4chan and empornium remains to be seen...

internet penetration varies by nation and region. one could simply see how reported rape rates vary nation-by-nation as a function of internet penetration at a particular threshold.

Any link of rape to urbanisation, with which availability of porn also correlates? (And incarceration rates?)

If you were going to commit rape you might think the best place to do it is in the country - nobody is about. But it is more common to read news stories of rapes in urban environs, in the victim's bedroom if it's date rape or urban parkland. Either that the victim is picked up in an urban area and taken by car to a rural location.

Obviously, in an urban environment there are more targets for rape. That could be the "pull". OTOH in urban areas there are many more people around to be potential witnesses of the crime. So why do they risk it?

Perhaps "safety in numbers" plays a role: the number of potential offenders within a 10 mile radius of a city would be much higher than in a rural area. In a rural community locals will have a good idea of the behaviour of people they know, and be able to point the finger.

Like cases of sexual abuse, more often the offender is someone the victim knows (close friend of family, member of the family) because the offender believes that closeness affords some sort of protection from getting caught.

So the city affords some anonymity which the rapist believes is a shield against getting caught. If this is the case better policing, CCTV and the practice of locking up rapists for long jail terms should result in a fall in rape in urban areas, even as access to porn rises.

This is why I love this site.

I agree with toto's comment on the operationalization of pornography, and razib's take on how a further analysis could be conducted.

There are not that many sites that allow thoughtful discussion of methodological issues that people actually care about. This is one of them.

I don't know whether it's allowed to link to one's own blog here, but there I've discussed a paper which does pretty much what razib has in mind using US states as the unit of analysis. Alas, I conclude that we ultimately learn little from it given its weaknesses.

I think it would only cloud the matter to look at availability of the internet. We want to measure something that's very close to "looking at porn." Playboy circulation (or all dirty magazines combined), box office receipts of X-rated movies, sales of dirty VHS tapes / DVDs, etc.

There's too much else that is associated with adopting the internet -- especially looking cross-nationally.

And again, that would force us to look at a very narrow time-period, roughly 1994 to the present. We can't make sense of what causes forcible rape to go up or down unless we look at least back to the late '50s or early '60s when the most recent crime wave began.

What makes the BJS more reliable?

Everytime a group of men huddle together, then print out stories what is good for women, you know, "reports" like oral sex is way better than the conventional one, nevermind that the act itself is demeaning and perverted, I want to take out my razor blade and just slice and dice all these men who calls "feminists" moronic.

:)