Is there any correlation between national prosperity and percentage of Christians?

I have heard of anecdotal evidence suggesting that the proportion of Christians in a population directly (positively) impacts national prosperity. In other words, the more Christians in a nation, the richer the nation becomes. Possible current examples include India and China which are apparently seeing both an increase in the proportion of Christians (India / China ) and in prosperity (India / China ). This would seem to follow the Biblical pattern, see e.g. Haggai 1 . But **is this a real phenomena**? Can we see a genuine correlation? And if so, what is its cause? **Note:** in light of comments and answers so far, this question is about *Christianity*, not *religion generally*. Other resources: - Christianity by country - Christian population growth