> what force but economic globalization could cause something like that?

This is a good observation. One possibility is that globalism serves as a vector for communicating certain cultural habits. A natural place to look is the US as it has been the primary globalizing force in recent history. American popular culture (TV, cinema), NGOs, the influence of American universities, etc. all serve to spread ideas sell a certain vision of life. It doesn't matter if the ideas are good. These methods appeal to the emotions.

And this is not a bad suspicion, as it seems that the inverse relation between number of children and wealth, when people are otherwise permitted to have children as they wish, seems to be characteristic of consumerist societies.