What are economists learning about religion?

More great stuff over at Marginal Revolution. The following is an excerpt that presents some of the results of a study on the economics of religion by economist Robert Barro:

1. Religious participation is negatively correlated with economic growth.

2. For the most part religious belief (as opposed to participation) is not correlated with economic growth. Belief in hell is positively correlated with growth, however.

3. Religious pluralism makes people more religious. In other words, the more options available, the more likely that religion will be found appealing.

4. As a country becomes wealthier, its people tend to become less religious (the U.S. is an outlier here; we are remarkably religious for our level of wealth).