Here's an interesting paper by an economist, Michael McBride, at UC Irvine. He addresses the issue of whether religious participation should decrease as societies grow wealthier. People have long predicted that religion should decline in increasingly wealthy societies because increased secularlization should decrease demand for religion. Also, the better off live is in this life, the more difficulty we should have in thinking about the next life.
The paper is rather technical (I think economists get commission for every equation that they use), but his conclusions are pretty straightforward.
He finds that yes secularization & wealth decrease the demand for religion in some ways, but in other ways they increase it. Specifically, increased wealth allows religious groups to promote themselves more effectively. It also creates inequality in society which motivates people to find comfort in religion.
Thanks Jay for the link!