Measuring religion from behavior: violence, climate shocks and religious adherence in Afghanistan

Religion plays a fundamental role in society but is often difficult to measure. We develop a novel method for measuring religious adherence that is based on decreases in digital activity during periods set aside for prayer. We apply this approach to a dataset of roughly 23 billion phone calls to study the determinants of religious practice in Afghanistan. We find that religious adherence declines after violent attacks by Islamist insurgents but increases in response to droughts in agricultural regions. This approach creates new avenues for studying religious behavior in contexts where conventional data are unavailable or unreliable.