China is undergoing at least three intertwined transitions. The demographic transition
refers to the change from high and fluctuating birth and death rates to relatively low and
stable ones. Control of infectious disease—which was central to the decline in death
rates—also spurs the epidemiologic transition to chronic disease as the primary health
threat, associated with urbanization and more affluent and sedentary lifestyles. These in
turn are linked to China’s third, economic transition from an agricultural and once
centrally-planned economy into a middle-income, market-based economy. The legacy of
this transition is still evident in large urban-rural differences in work and social welfare
entitlements.