Compare methods

	Religious Pluralism Index	Religious Economies Analysis
Field	Sociology Of Religion	Sociology Of Religion
Family	Process / pipeline	Process / pipeline
Year of origin	2002	1987
Originator	David Voas, Daniel V. A. Olson & Alasdair Crockett (critique); religious-economies tradition	Rodney Stark & William Sims Bainbridge; Roger Finke
Type	Diversity/concentration index for religious composition	Supply-side economic analysis of religious markets
Seminal source	Voas, D., Olson, D. V. A., & Crockett, A. (2002). Religious Pluralism and Participation: Why Previous Research Is Wrong. American Sociological Review, 67(2), 212-230.	Stark, R., & Bainbridge, W. S. (1987). A Theory of Religion. New York: Peter Lang. ISBN: 9780820403564
Aliases	Religious Diversity Index, Religious Fractionalization Index, Herfindahl Religious Concentration Index, Denominational Pluralism Index	Religious Market Model, Supply-Side Theory of Religion, Religious Economy Model, Rational-Choice Theory of Religion
Related	3	3
Summary	The religious pluralism index measures how religiously diverse a population is by computing the probability that two randomly selected people belong to different religious groups. It is the religious application of the Herfindahl-Hirschman concentration measure: one minus the sum of squared denominational shares, ranging from zero (a single dominant group) toward one (many evenly sized groups). The index became central to the sociology of religion because the religious-economies paradigm predicted that greater pluralism, by signaling competition among firms, should raise participation. David Voas, Daniel Olson, and Alasdair Crockett's 2002 American Sociological Review article showed that much of the prior literature testing this claim was undermined by a mathematical artifact linking the index to participation, making careful construction and interpretation of the index a methodological topic in its own right.	Religious economies analysis treats a society's religious life as a market in which competing firms (denominations, sects, and movements) offer products to consumers (potential adherents) under varying degrees of state regulation. Developed by Rodney Stark and William Sims Bainbridge in A Theory of Religion (1987) and elaborated by Stark and Finke in Acts of Faith (2000), the framework inverts the older secularization assumption that modernity erodes religious demand. Instead it holds that latent demand for religion is relatively stable, and that observed variation in religiousness across societies is driven mainly by the supply side: how many religious firms compete, how specialized and energetic they are, and how heavily the state regulates the market. Where competition is open and unregulated, vigorous firms mobilize participation; where one firm enjoys a state-protected monopoly, it grows lazy and overall participation falls.