The Demographic Transition is modern but the age of family formation is actually used by historians to track how stressed the social contract is. Families have always been expensive and delaying them has always been a last resort for expense management.
This sounds interesting but I couldn't find any sources in a few seconds of searching. Got any resources for further reading?
Not an expert at all, so mostly a question. I have often heard the opposite, where large families are more common in less developed countries because having many children acts as insurance/social safety net for when parents become older and more frail. How does that relate?