Unlucky to have brothers: Sibling sex composition and girls' locus of control

We explore the relationship between sibling sex composition, gender inequality and girls' locus of control. Among girls aged 10-15 in China, girls with brothers are lower in internal locus of control than girls with sisters, i.e., they believe that success depends more on external forces than on their own effort. We ascribe it to parental son preferences based on evidence about parents' evaluations of the importance of continuing the family lineage and the stringency level of fertility policies. The channel is that parents allocate fewer productive resources, e.g., after-school tutoring and parental school involvement, to girls when they have sons. Our findings highlight that gender inequality may cause negative impacts on girls' locus of control.