Tyler Cowen, in the course of answering an inquiry as to why there are so many churches in Las Vegas, writes:

I would think that most of the churches in Las Vegas are for the residents, not the tourists, and thus the quantity of sin is not a major factor. Why should the residents be especially sinful? (Don’t forget that lots of sinful activities seem to be produced at constant returns to scale, so there’s not always free-riding upon the sin infrastructure for tourists plus parking is an issue.)

Free-riding upon the sin infrastructure. Beautiful.