[NoLinkToMe]

Sorry for the late reply.

For me it's different. For one it's like you said: friends that never left the rural areas have kids more often.

But also friends that I grew up with in urban environments, left to rural environments around the time of having kids. Those that didn't, stayed.

It seems that those who preferred to spend more for the cultural offering of the city stayed and optimised their time to enjoy that cultural offering by not having kids (bars, cafes, museums, hobbies, sports, travel, career).

While those that preferred family life, chose to optimize for that by moving to a place where housing was more affordable, allowing less time spent on career, more time spent on family.