9. Religion and Demography

Religion and demography are a contested space. Every country in the world is interested in how its demographic numbers are changing over time, and yet they are acutely conscious of the rise of religion (Iyer 2016; Lehrer 2009). Whether there were early concerns about a ‘population bomb’ or worries about ‘minority fertility rising’, the subject of religion and fertility has not gone away and indeed seems to reappear in different periods of world history repeatedly. In this chapter, I discuss why we should be interested in the question of religion and demography. I provide an overview of recent trends in the world’s religious demography and then locate this within the historical context of what major world religions continue to think theologically about factors that affect demographic decisions. The focus is on the various mechanisms through which religion might affect fertility behaviour. I then distinguish between the various channels through which religion also affects mortality, especially through its effect on physical and mental health behaviours. I put forward the view that religion continues to have important consequences for fertility and mortality decisions which collectively affect a country’s religious demography overall.