The argument your link makes is that Singapore has low fertility therefore cities are bad, and I&#x27;m not being reductionist here that is literally all the content to be found there.<p>How do you uncouple the effect that the people moving into cities have on the city fertility rate from the effect the city has on the fertility rate of the people moving into it? Cities offer things that are valuable to people who don&#x27;t want children (like, high utility activity for the time they aren&#x27;t spending raising the children they don&#x27;t have, compared to places that aren&#x27;t cities) so they are especially attractive to people who don&#x27;t want children, and you would expect any place that is attractive to people who don&#x27;t have children to have a low fertility rate.