I came across this interesting study by Abrams, Yaple, and Wiener, “A mathematical model of social group competition with application to the growth of religious non-affiliation”.
When groups compete for members, the resulting dynamics of human social activity may be understandable with simple mathematical models. Here, we apply techniques from dynamical systems and perturbation theory to analyze a theoretical framework for the growth and decline of competing social groups. We present a new treatment of the competition for adherents between religious and irreligious segments of modern secular societies and compile a new international data set tracking the growth of religious non-affiliation. Data suggest a particular case of our general growth law, leading to clear predictions about possible future trends in society.
And the trend is that religious affiliation is declining, and will keep declining towards Zero. I like that study already ! The fulltext can be found here.
Now, I have a minor quibble with this study, and you will see what I mean when I quote you the opening paragraph :
The tools of statistical mechanics and nonlinear dynamics have been used successfully in the past to analyze models of social phenomena ranging from language
choice [1] to political party affiliation [2] to war [3] and peace [4]. In this work, we focus on social systems comprised of two mutually exclusive groups in competition
for members [5–10]. We compile and analyze a new data set quantifying the declining rates of religious affiliation in a variety of regions worldwide and present a theory to explain this trend. People claiming no religious affiliation constitute the fastest growing religious minority in many countries throughout the world[11]. Americans without religious affiliation comprise the only religious group growing in all 50 states; in 2008 those claiming no religion rose to 15 percent nationwide, with a maximum in Vermont at 34 percent[12]. In the Netherlands nearly half the population is religiously unaffiliated[13].
Boldface mine. That’s just nonsense. Most people without religious affiliation(whichever way that is actually defined) are not religious, they don’t buy into religious nonsense, and are either atheist or agnostic. So it’s grotesque to call them the “fastest-growing religious minority”. But let’s leave that aside, I hope it can get corrected by the authors at some point.
In their model, the authors assumed that attractiveness of a group increases with the number of members, and that “attractiveness also increases with the perceived utility of the group, a quantity encompassing many factors including the social, economic, political and security benefits derived from membership as well as spiritual or moral consonance with a group.”
They then crunched the numbers and came up with this conclusion :
We found that a particular case of the solution fits census data on competition between religious and irreligious segments of modern secular societies in 85 regions around the world. The model indicates that in these societies the perceived utility of religious non-affiliation is greater than that of adhering to a religion, and therefore predicts continued growth of non-affiliation, tending toward the disappearance of religion.
Have a look at the fulltext yourself. I can’t find much wrong with their study design and conclusions so far. But obviously atheists reading this study should be cautious of confirmation bias. The one objection I have, is that this study only applies to Western countries. What would make me even more happy, is a study showing that in Islamic states religious affiliation is also seen as something with limited utility. But I can’t see that being the case right now.