China's migration share is calculated using the Residence Status of the Population by Region, i.e. whether the individual resides within the area of residence status, from China’s Statistical Yearbook’s demographic section.
China's export measure by province is calculated by using the Exports Value of Commodities by the Place of Their Origin from China’s Statistical Yearbook's foreign trade section. The export data includes 31 regions (22 provinces, 5 autonomous regions, and 4 municipalities)