Today there's a new report out about how population growth is going down in the United States. Immigrant women are having fewer children. It shows that if you just let women from the developing world have the same rights - or, rather, access - that we have, they make smart decisions.

It's against the law in India to marry off a girl under the age of 18, as it is in many parts of the world. But India has more child brides than any other country, and they become mothers early in life. The population continues to grow; it is likely to overtake China as the most populous nation within this decade.

In the south of India, they educated girls. Three things came together in southern India that are unbelievably coincidental. There, the local Maharajas believed in education for everybody. The Syrian Catholic Church built schools for boys and girls. And then the Communist party, which took over politics for a period of time, had very strong social policies that benefited women. As a result, girls got into school. It was the first part of the country where towns could claim to be 100 percent literate. And so there, you're going to have a sex ratio at birth that's normal.

The ratio of boys to girls is bad in three big countries in Asia: China, Vietnam, and India. It's worst in the north of India, where there's horrendous poverty. The number of girls in many of these places is so low that it has social consequences. You get young men without jobs and without women, and this leads to chaos and political danger. But the south of India is very different.

What's a problem with India, in particular, is female feticide - aborting a female fetus. It is unacceptable and illegal, but it happens on a large scale. Then there's also the killing of baby girls. Female feticide is pretty much middle-class, Indian experts say. This is not happening among the poor; they just have to keep bearing children and hope they live. This casts into doubt the spurious argument that we just have to wait until everyone's middle class and then all of this will sort itself out. Better-off women will have fewer children - but at what cost?

Today there's a new report out about how population growth is going down in the United States. Immigrant women are having fewer children. It shows that if you just let women from the developing world have the same rights - or, rather, access - that we have, they make smart decisions.

The whole world population rests on women. You have to start with the woman. And the woman will make her own decisions. If you want to have five or ten children, fine. You can have big families or small families, but you have the family you feel you can afford or feed. In China the one - child policy is already finished - on its way out because the economic conditions end up producing the same effect. If people want an expensive flat in a place like Shanghai, you can't have more than one child or two.