The aim of this article is to assess, from an empirical point of view, the relative explanatory capacities of two hypotheses that address the link between economics and religion: the religious markets and the secularization hypothesis. First, we estimate a baseline model that takes into account both hypotheses jointly. Secondly, we study in a separate way the influence of socioeconomic development and market structure. Finally, we investigate the relationship between group size and religious commitment. Overall, the results suggest some supporting evidence for the predictions derived from the hypothesis of religious markets that emphasize the over-riding importance of the degree of competition as a determinant factor of religious behaviours.