[jjeaff]

Many if those things have negative externalities. More guns, more violence. More prostitution, more human trafficking and other abuse (same for pornography). more illicit drugs, more trips to the emergency room and more deaths, etc.

[rrobukef]

It seems to me that all your examples involve people with less chances in life. However, the primary drive for criminality and prostitution is poverty. Less poverty means the supply of dealers, prostitutes shrinks, with rising demand prices will shoot up.

More guns, more violence by a smaller group, thus easier to the police. More prostitution by a smaller group, thus driving prices up which allows an easier escape. More human trafficking, why? This is hardly a side-job. Do you mean an increased immigration?