Black, Sandra E.; Devereux, Paul J.; Salvanes, Kjell G. - 2021
Norway and focuses on one family characteristic: the effect of family size on IQ. Because of the endogeneity of family size …, we instrument for family size using twin births and sex composition. IV estimates using sex composition as an instrument … show no negative effect of family size; however, IV estimates using twins imply that family size has a negative effect on …