parity progression ratio

The question of whether parents have preferences over their children’s sexes has long been of interest to economists and demographers. In this study, we first investigate the presence of these preferences among Iranian parents. Then, having established its existence, we next turn to characterize the quality of sex preference. There are two widely used methods for addressing this issue in the literature. The first is to estimate a Logit model which relates the probability of the birth of a new child to the sexes of its elder siblings. The second is to estimate a proportional hazard model that links the time interval before each birth to the sexes of preceding children. This study makes use of both methods. The results confirm the existence of sex preferences in Iran. Iranian parents are shown to favor a rather balanced mix of boys and girls, though boys seem to be slightly preferred over girls.