Spatial filtering analysis of sex ratios at birth in China

China has a widely distributed rising SRB since 1980s. Linear regression and spatial filtering on provincial and county scale SRB are implemented to explore the relationship between SRB and four factors: economy, education, culture and family planning policy of China. On the province scale data, the policy variables have similar explanation effect of fertility ratio on SRB, and the family planning policy has much greater effect on the SRB of the second parturition than that of the first parturition. The SRBs on whole, the first and second parturition are spatial autocorrelated, so are the SRBs at city, town and rural areas. On the county scale data, more strong spatial effect is detected. Linear regression and spatial filtering are applied on five selected provinces with very high SRB and SRB on the second parturition. Semiparametric spatial filtering is an efficient approach to deal with the spatial dependencies among SRB and relative data.