Does the marriage market sex ratio affect parental sex selection? Evidence from the Chinese census

Recent increases in the (male/female) sex ratio at birth in eastern Asia are thought to be associated with a preference for sons and to result from parental sex selection. However, males are less likely to marry and to have offspring as the ratio increases, and that decreases the expected number of grandchildren. Using data from the 2000 Chinese census, we test whether the sex ratio in the marriage market has an effect on the gender of subsequent births and hence on the sex ratio of the birth cohort. The slow population growth caused by the Great Famine in the early 1960s and the quick recovery that followed produced major changes in the sex ratio for those of marriageable age two decades later. We estimate that an increase of 1 % in the number of marriageable males relative to females, the marriage market sex ratio, would decrease the probability of having a son by 0.02 percentage points. That implies that the Great Famine, which occurred around 1960, led to an increase in the early 1980s of 5.8 extra male births per 100 females.