> Poorer populations have less access to sex education.

This is likely an accurate thesis based on macro and micro studies.

TLDR Education, empowerment (contraceptives), labor force participation = decline in fertility rate. Provide access to all of the above, fertility rate drops off.

https://ourworldindata.org/fertility-rate#what-explains-the-... (Fertility Rate: What explains the change in the number of children women have?)

Outside of Africa, there are only a handful of countries where the fertility rate is > replacement rate.

https://ourworldindata.org/grapher/children-per-woman-un?tim...