Sharif Digital Repository

This thesis aims to the study of quality-quantity trade off in the family through investigating the effects of family size and birth order on their educational attainment. The latter has been chosen as a criteria for measuring the quality; to measure the effects of quantity we have used the twins for the instrumental variable as an endogenous shock in the family size to reduce bias that happens as a result of omitted variables bias and to measure the effect of family size on it’s quality more accurately. We have also used censored regression to eliminate the bias of student children in the sample.In addition to concentrating on the differences between children of different family sizes we...