Religious market share and intensity of church involvement in five denominations

Proponents of the supply side approach to religion theorize that religious market share- the proportion of people in a geographical aarea who belong t o a given denomination- is inversely related to religious commitment in tha t denomination. They argue that a small market share motivates religious le aders to compete harder in the religious market place, increasing the parti cipation of members. Another perspective, often associated with secularizat ion theory, make the opposite prediction. It argues that people find it dif ficult to remain religiously committed in social environments where they ar e numerical minorities because other people do not reinforce their beliefs and practices. We use data from a large study of financial giving to analyz e the relationship between market share and commitment for five denominatio ns in the United States. We find that market share has a negative effect on church financial giving within all five denominations and a weaker negativ e effect on attendance in three of the denominations. We explore whether th ese effects are the spurious byproducts of pro-religious cultural norms ass ociated with either the South or the presence of conservative Protestants i n local areas. In model pooling all denominations, the negative effect of m arket share on financial giving and attendance cannot be explained away by either of these factors. However, the effect on attendance can be accounted for by congregational size.