Is there another variable which could explain both the increased “religiousity” and the run up in prices?
For example: the run up in prices is caused by either increased demand or constraints on supply. As some have noted, the supply constraints can be cause by regulation (perhaps to achieve an environmental goal). The increased demand may be caused by the economic health of a community which lures additional workers to the area.
Your analysis begs the questions:
* is religiousity correlated with less economically viable regions or less job growth?
* if so, is there an underlying quality that promotes both economic health and a lack of religiousity?
