Another project, Forecasting Religiosity and Existential Security with an Agent-Based Model, examines questions about nonbelief: Why aren’t there more atheists? Why is America secularizing at a slower rate than Western Europe? Which conditions would speed up the process of secularization—or, conversely, make a population more religious?

Shults’s team tackled these questions using data from the International Social Survey Program conducted between 1991 and 1998. They initialized the model in 1998 and then allowed it to run all the way through 2008. “We were able to predict from that 1998 data—in 22 different countries in Europe, and Japan—whether and how belief in heaven and hell, belief in God, and religious attendance would go up and down over a 10-year period. We were able to predict this in some cases up to three times more accurately than linear regression analysis,” Shults said, referring to a general-purpose method of prediction that prior to the team’s work was the best alternative.