"The current study finds that societies which historically engaged in plough agriculture today have lower fertility. We argue, and provide ethnographic evidence, that the finding is explained by the fact that with plough agriculture, children, like women, are relatively less useful in the field....

"Medical research indicates that breastfeeding suppresses post-natal fertility. We model the implications for breastfeeding decisions and test the model's predictions using survey data from India. First, we find that breastfeeding increases with birth order, since mothers near or beyond their...

Son preference is known to be found in certain types of cultures, that is patrilineal cultures. But what explains the fact that China, South Korea, and Northwest India manifest such extreme child sex ratios compared with other patrilineal societies? This paper argues that what makes these...