A lot of good objections raised, and I’m happy to discuss the pernicious effects of current porn (which is the yardstick we should use—it has changed a lot over the last fifteen years). However, this study only examined porn usage as it relates to instances of rape, and the result seems unambiguous: porn does reduce rape. As I stated above, increased porn consumption comes both at a price and with a prize. This positive effect, I suggested, we can count in its favour, and then continue discussing what should be held against it.
The problem with these types of lumpen-empirical studies, imagining and constructing a direct causal immediacy, much like Skinnerian behaviourism/stimulus-response/operant conditioning "studies", is of course not only their self-serving selectivity, but their intoxicating ignorance of political, social, economic and cultural forces. The sheer, contradictory hilarity of, for instance, such reasoning as (in the article quoted by Guybrush above): "Next, violence. What happens when a particularly violent movie is released? Answer: Violent crime rates fall. Instantly " is indicative of this myopic, what-you-see-is-what-you-get mindset.
Well, along similar lines, what happened instantly when everyone watched 9/11 as a reality TV show on 9/11? Crime in the U.S. collapsed. Instantly. Do we therefore conclude, therefore reason, that terrorism is a "cure" for violent crime? Or do we possibly conclude the very opposite (based on a wider, cultural, analysis, not to mention the subsequent events, an explosion of violence throughout the world, still growing***)?
Isn't, instead, terrorism (perceived to be) violence at its most horrific, at its purest? Just as porn is rape/sexual violence at its purest? It is meaninglass double-speak to therefore claim that porn "reduces" rape, or alternatively that violence reduces crime, war reduces conflict, etc. This is (suicidal) replicant ideology at its purest: the very thing causing the problem is the solution to the problem.
***As we know, that event in the U.S. led to a (racial) displacement of crime/violence. Changes in the public's perception of Muslims, Arabs, and related groups quickly after 9/11 began manifesting on the streets and in offices. In the months immediately following 9-11, hate crimes against Muslims shot up to 34 times their pre-attack levels, according to FBI reports. The Arab-American Anti-Discrimination Committee (ADC), based in Washington, D.C., reported that hate crimes against people believed to be of Middle Eastern descent increased 40 times before dropping to about double the former rate—and that rate has held steady.
EDIT: "meaninglass": oh, what a wonderful Freudian slip.