It's worth noting that the authors here do not claim that it reduced rates, only that it coincided with such a reduction, i.e that the material did not cause an increase in child sex crimes. The catharsis effect has very little empirical support.

As such, this paper does dispute the argument that porn leads to higher rates of sexual assault. It does not provide evidence for porn being an outlet that prevents crimes. The distinction is important.

Thanks for sharing this research! My hunch is that it is a local optimization. Perhaps if we focused on de-stigmatizing mental health issues and making access to mental health care easier, that could also reduce rates. It is a universal and much less problematic strategy.

That reads like you are simply ignoring any information you disagree with. For the sake of argument let’s assume it’s the best possible option on any scale you choose, now what do you feel should be done?