There's a post on porn and rape that's making the rounds (among the blogs I read, at Half Sigma and Roissy so far). The author claims to show that a greater availability of pornography is associated with lower rape rates. But it is not -- nor are the two directly related. They simply appear unrelated altogether.

First, the original post's author is not an idiot; he just made an honest mistake in getting his crime data. (And he is right in his side-point about how moronic feminists are when they suggest that rape has little to do with meeting the guy's sexual urges.) But let's focus on what the crime data say.

The Bureau of Justice Statistics website has a page of summary statistics that includes the graph in his post that shows what looks like a decline in the rape rate from the early-mid 1970s until today. Those data appear to be from the National Crime Victimization Survey, and one drawback here is that minors are often questioned in the presence of their parents or guardians. They're much less likely to report something embarrassing and painful as rape when the adults are there, especially if it was a family member or acquaintance of the family, as is typical. And young females are the most at risk. The definition of rape there seems too broad also, including attempted rape and psychological intimidation -- what people really have in mind when they hear "rape" is someone using physical force to gain sexual access to another person.

Luckily, though, the BJS also has data on the forcible rape rate ("real" rape), and this series goes back even further than the NCVS data -- back to 1960. What do these data say? If you're a regular reader, you already know because I've reviewed the change in violent crime and forcible rape rates before. Go to that post to see the graph and get the details. In brief, there was a sharp rise from about 1964 through 1992 and a decline thereafter.

What was the change in porn availability from 1960 to 2006? I've reviewed that topic too. Again, go there for the graphs and details. Looking just at Playboy to stand in for pornography generally, its circulation in 1960 was about 1 million and shot up to 7.2 million at its peak in 1972, dropping to 3 million by 1987, where it has stayed since. Population size isn't the main factor here since the US population did not multiply by 7 between 1960 and 1972. There was an explosion in Playboy circulation, and even through the 1980s it was still 3 times as high as in 1960. Therefore, from 1960 to 1972, there was a surge in porn availability and a surge in the forcible rape rate. This much of the data contradicts the "more porn, less rape" idea.

But Playboy circulation dropped sharply from 1973 to 1987, and that didn't cause the rape rate to drop. Its circulation has remained pretty steady since 1987, while the rape rate has steadily fallen since 1992. There are other data in the above post from the General Social Survey on what percent of men have watched an X-rated movie in the past year. Again there are no clear patterns that suggest an association with the forcible rape rate. If anything, the availability of porn has increased since the mid-late 1990s with the adoption of the internet. That suggests the "more porn, less rape" idea since rape was falling -- but it had peaked in 1992, about a half-decade before most guys had easy access to internet porn.

Putting all of the data together, it doesn't look like there's a relationship at all between availability of porn and the forcible rape rate. It's trivial to choose a time period in which your preferred hypothesis pans out, but looking at the big picture is always more revealing. In this case, we discover a big let-down -- neither side is right, and rape has little to do with porn. Debates like "porn and rape" or "poverty and crime" serve mostly as a full employment plan for gasbags. What if the two things aren't related in the first place? Well, that's a pretty boring debate -- way to rain on our parade.

Labels: crime, History, porn