The poverty trap with high fertility rates

The aim of this paper is to clarify the causes of the poverty trap resulting from a negative correlation between income and fertility, in a manner that is consistent with the data across and within countries. This paper points out that a higher fertility rate is the cause of the poverty trap, because of its educational cost aspect. For useful comments and suggestions, I am indebted to Koichi futagami, associate editor Eric Hanushek, Tatsuro Iwaisako, Akira Momota, Testuo Ono, Yoshiyasu Ono, Makoto Saito, and the anonymous referees of this journal. Of course, any remaining errors are all my own