THE SLOWING OF CHURCH GROWTH: Check out this paper presented in 2002 at the Association for the Sociology of the Religion. I expect that only our Scientist and the Antiquarian (who moonlights as an economist, I am told) can actually walk through all of the statistical analysis. However, even for those inclined to the humanities this is definitely worth the read. Just skim over the statistical jargon.
Here is the basic gist of the article. In 1980 Rodney Stark presented a paper in which he argued that the Mormonism was the first new, global religion since Islam rode out of the desert. In support of this claim, he put together a statstical growth model of the church based on past growth that predicted over 200 million members by 2080. In 1990 or so Mormons who were aware of Stark's thesis were euphoric because church growth had significantly exceeded Stark's predictions. In the 1990s, however, things changed. Despite vast growth in membership and missionaries, the number fo baptisms remained fairly constant, which means that church growth was declining in terms of percentage growth.
Stark's predictions were based on an exponetial growth model, which means that the Church was supposed to growth at a fixed percentage every decade. (I think for Stark's predictions it was about 40%). Loomis argues that what we are actually looking at is a growth spike in the 1970s and 1980s when the Church increased exponentially, but that now its growth is settling into a linear pattern. Thus, under Loomis's model we end up with something like 30 million members in 2080. Loomis posits several factors that account for the end of exponential growth -- lower rates of births into the Church (probably a combination of lower real birth rates and inactivity), increased religious competition, and a less "productive" membership base as the demographic shifts away from pioneer decended population to a recent convert and inactive population.
Perhaps one of the most interesting points that Loomis makes draws on an idea that Stark has pushed elsewhere: religious tension. Here is the theory. New religions start out having extremely tense relationships with their surrounding cultures. Eventually the tension subsides a bit and initially this lessening of hostility is good for growth. Over the long term, however, the loss of tension tends to slow growth. Sound familiar? Thus, it may be that certain kinds of retrenchment away from distinctive Mormon practices -- polygamy, the ban on black's in the priesthood, etc. -- have been good for Mormon growth, but that at some point the pendulum swings too far and the loss of distinctiveness hurts growth. Interestingly, during the 1990s -- a period when the Church in some ways (more on this below) has been emphasizing its "Christianess" -- our Christian competitors in the religious marketplace (Pentecostals, Seventh-Day Adventists, etc.) have had increasing growth rates.
On the tension issue, I am of two minds. Obviously, the twentieth century saw a huge reorientation of Mormonism, and in the last decades of the twentieth century one could make a persuasive argument that Mormonism was running as fast as it could towards respectability in the form of an essentially Protestant venier. The evidence for this would be the new subtitle for the Book of Mormon, the general emphasis on Christ in our teachings, the change in the church logo, and the ill fated attempt to change the short name of the church from "Mormon Church" or "LDS Church" to "Church of Christ," modifications in the temple endowment, etc. Without denying this, however, I think there is another strand at work here. Much of the increasing emphasis on Christ comes from an increased emphasis on the Book of Mormon. The same goes for the protestantizing theology of folks like Stephen Robinson. Furthermore, one of the most striking things about the late 20th century was the HUGE proliferation of temples, which -- despite the changes in the endowment -- remain the instantiation of the most radical elements of our theology. Furthermore, I think that the 1990s also saw an big upswing in hostility toward Mormons on the part of Protestants, something that I think has the salutory effect of reinforcing Mormons' sense of difference and distinctiveness.
Certainly, the Church hierarchy seems well aware of the issues that Loomis discusses, for all of our triumphalism. The missionary program is undergoing major changes. The PEF is part -- I think -- of a wider awareness that we are doing a good job of transforming new converts into missionaries, but need to focus on turning returned missionaries into stable Mormon fathers and mothers who produce a strong core of second and third generation Mormons. Perhaps, this century will also see the triumph of the more radical temple and new scripture strand of the Church's emphasis in the last part of the 20th century. Stay tuned...
Regardless, you ought to read the Loomis article, if for no other reason than the fact that the Stark article is a classic. I have always loved Stark's image of a New World Religion. It goes well with my own particular hopes and ambitions. On the other hand, Stark's predictions have always seemed a bit rosy to me. (A point I obliquely made in my first ever publication in the FARMS Review of Books.) It is interesting to see a criticism from some one with a bit more sophistication than myself.