Spatial Variation of Juvenile Sex Ratios and Sex Selective Underreporting in Two Chinese Censuses

William Lavely, University of Washington
Yong Cai, University of Washington

The sex ratio of children in China, as measured by official censuses and surveys, has been on the rise since the late 1970s. National level trends in the missing girls phenomenon and sex-selective underreporting have been well described, but regional and local variations are less well known. This paper uses data from the 1990 and 2000 censuses of China in conjunction with Geographic Information System (GIS) technology and spatial statistics to describe sub-national variation in the juvenile sex ratio and in sex-selective underreporting. We first visualize the spatial patterns in juvenile sex ratio and sex-selective underreporting, then use spatial statistics to detect clustering of these same phenomena. Spatial autocorrelations, global and local, are used to describe spatial patterns and to detect clustering. We present preliminary models of spatial variation, and conclude with a discussion of social and political explanations for the observed patterns.