Josh,

1. My intuition is, that viewing pictures is more a tension relief and prevents the real offence, rather than stimulating the crime. I would prefer to have hard scientific data. However, without those data, I would bet money on my stated hypothesis, rather than the opposite.

2. You should cite more sources, preferred are the research paper, and among them, metaanalyses, as ChristianKI correctly says.

3. I am not from USA, but worked there for 2 years in the past. I remember hearing about people facing prison for the possession of children pornography, and was genuinely surprised and sorry for the offenders (although I am a standard heterosexual woman). We had a long discussion with my that day US boyfriend, why is the possession punished so severely. I was surprised by the unproven, but unquestioned assumption, that having pictures stimulates the owner to commit the actual crime. Of course, pictures of children molested or having sexual intercourse should not be taken, because children should not have sexual intercourse or be molested. However, some people define children pornography very broadly, even children taking a bath, running around naked in the garden etc. Some 35 years ago, my parents photographed me naked on the beaches of Yugoslavia and it was pretty normal at those times. I would not be happy, if they were selling those pictures to strangers for pornography. However, I believe, selling their own old pictures when the child becomes adult could become legal once - if it is proven that the pictures do not increase the crime.