It's probably a little bit of both. Birth rates have dropped on a per-capita basis since the onset of the Great Recession. People hold off on having kids when times are tough, but things are kinda dragging on these days with little hope of significant prosperity on the horizon so now younger people are having families regardless of the situation with society.
It's kinda like buying cars. Someone who needs to upgrade their vehicle can wait a few extra years before buying a new car, but eventually the thing dies and forces a purchase.