I think it might depend on whether one believes there is such a thing as non-explitative erotica. If not, then obviously you would think all porn is bad. If so, then one might draw more complex distinctions based on both content and the consumer population.
As it happens, rape began a slow but steady decline since the 1970s, a trend which sped up (that is, it declined faster) in the 1990s. It's been postulated that this might have something to do with the accessibility of porn over the Internet:
National trends are one thing; what do the figures for the states show? From data compiled by the National Telecommunications and Information Administration in 2001, the four states with the lowest per capita access to the internet were Arkansas, Kentucky, Minnesota, and West Virginia. The four states with the highest internet access were Alaska, Colorado, New Jersey, and Washington. (I would not have guessed this.)
Next I took the figures for forcible rape compiled by police reports by the Disaster Center for the years 1980 and 2000. The following two charts display the results:
TABLE 1. STATES WITH LOWEST INTERNET ACCESS <2>
STATE Internet 2001 Rape 1980 Rape 2000
Arkansas 36.9 26.7 31.7
Kentucky 40.2 19.2 27.4
Minnesota 36.1 23.2 45.5
W. Virginia 40.7 15.8 18.3
All figures are per capita.
TABLE 2. STATES WITH HIGHEST INTERNET ACCESS <3>
STATE Internet 2001 Rape 1980 Rape 2000
Alaska 64.1 56.8 70.3
Colorado 58.5 52.5 41.2
New Jersey 61.6 30.7 16.1
Washington 60.4 52.7 46.4
All figures are per capita.
While the nationwide incidence of rape was showing a drastic decline, the incidence of rape in the four states having the least access to the internet showed an actual increase in rape over the same time period. This result was almost too clear and convincing, so to check it I compiled figures for the four states having the most access to the internet. Three out of four of these states showed declines (in New Jersey, an almost 50% decline). Alaska was an anomaly: it increased both in internet access and incidence of rape. However, the population of Alaska is less than one-tenth that of the other three states in its category. To adjust for the disparity in population, I took the combined population of the four states in each table and calculated the percentage change in the rape statistics:
TABLE 3. COMBINED PER CAPITA PERCENTAGE CHANGE IN INCIDENCE OF RAPE.
Aggregate per capita increase or decline in rape.
Four states with lowest internet access Increase in rape of 53%
Four states with highest internet access Decrease in rape of 27%
I find these results to be statistically significant beyond the .95 confidence interval.
http://jurist.law.pitt.edu/forumy/2006/06/rape-porn-and-criminality-political.phpThis is not proof of anything, but it's certainly worthy of further research.
Personally speaking, I think that the porn industry is a Good Thing, insofar as openness and professionalism result in a safer environment for participants. by contrast, I think prohibition thereof increases the likelihood of exploitation.