Several Asian countries have experienced severe sex ratio imbalances. In order to normalize male-biased ratio,
local governments in China and India have offered a cash grant for giving birth to a girl. However, the effect of
financial incentive on the sex ratio at birth is not well understood in the literature. This paper investigates how
increase in economic value of a daughter affects the sex ratio of infants in Vietnam by exploiting a sharp increase
in cross-border marriages. The marriage between Southeast Asian women and East Asian men substantially
increased the economic return of having a daughter in Vietnam. Those marriages involve up-front payments
for brides’ family, which is more than twice the GDP per capita, and also sizeable remittances later. Using
nationally representative datasets of Vietnam, we find that the provinces with substantial marriage outflows had
seven less boys per hundred girls compared to the other provinces