This has happened to every single society [*] as it industrializes [0], and offering extensive support and incentives to parents (e.g. as has been tried in Scandinavian countries) does very little to reverse this trend [1, 2]. My hypothesis is that as societies industrialize, they afford their population more and more activities that are simply more fun and rewarding than having children. So many people I know put of…
I don't think the religion is the driver here.