The 2011 census has once again brought into focus the deficit of girls in India. While the census of 2001 had revealed that the child sex ratio, computed as the number of girls per 1,000 boys in the segment aged 0-6 years, had fallen to 927; in 2011 it has come down further to 914. A low sex ratio among children can be due to one or both of two factors. First, the sex ratio at birth may be lower (that is, dominated by males) than normal. Second, female mortality may be higher than male mortality during infancy and early childhood. Sex-selective under-enumeration can also create an imbalance in the enumerated population; however, with improvement in the quality of age-sex reporting in recent census enumerations, this issue has become less important.