The analysis will rely on
the data taken from roughly 500,000 deaths recorded at sites
between 1991 and 2000, and population counts by age and sex
that are used to convert the recorded deaths into city-level
mortality rates for ages 1, 5, and 10 y and 5-y increments through
age 80. Additionally, these mortality rates are used to calculate
an overall mortality rate based on China’s age distribution in
2000 and life expectancy at birth, both measured annually for
the 125 locations. In SI Appendix, we discuss why the results are
unlikely to be driven by mismeasurement in a location’s mortality
rate from either migration or the transfer of sick rural
residents to urban hospitals.