This paper analyzes the relationship between religious market product
variety and church membership. We find that denominational variety is
negatively associated with the total level of church membership in U.S
. counties. This result appears to contradict the standard religious p
roduct variety model. Our data are consistent with a more general view
of markets that incorporates the cost to consumers of product variety
. Where product variety has significant costs, an increase in variety
may reduce total market penetration. The paper suggests market charact
eristics that might give rise to this situation, characteristics prese
nt in the religion market.