Both rural and urban populations have economic and traditional incentives to prefer sons over daughters. Sons are preferred as they provide the primary financial support to the parents. A woman changes her surname to her husband's surname after marriage. For some families, one's daughter-in-law's name instead of a daughter's name would be added in the book of family tree.
Therefore, if a family had no son, the fortune and name of the family would have no legal heirs. The choice of small families also affects the people's views on the sex of their child.