First to summarize what he says:<p>It used to be short life expectancies led to people having  more children. Not anymore, as most countries are in the high life expectancy group.<p>Basically better family planning, womens rights, and health care leads to higher life expectancies leading to: SMALLER FAMILIES.<p>Now I will add:<p>i) Divorce laws, and strict enforcement of it. I think this contributes heavily to lowering populations. But you need that because of point (ii) below.<p>ii) The lack of religion leads to a lifestyle that breaks down the family unit. Once the patriarchal mode of life goes out of the window, so does the population growth. In other words, women's rights. So its a trade-off.<p>I'm looking at you Europe.