Barro and McCleary (2003, Religion and economic growth across countries. American Journal of Sociology 68: 760–781) is a key research contribution in the new literature exploring the macroeconomic effects of religious beliefs. This paper represents an effort to evaluate the strength of their claims. We evaluate their results in terms of replicability and robustness. Overall, their analysis generally meets the standard of statistical replicability, though not perfectly. On the other hand, we do not find that their results are robust to changes in their baseline statistical specification. When model-averaging methods are employed to integrate information across alternative statistical specifications, little evidence survives that religious variables help to predict cross-country income differences. Copyright © 2011 John Wiley & Sons, Ltd.