The evolution of only-child family structures in China: an analysis based on life tables

Abstract Amid persistently low fertility rates, the population of only children in China has increased rapidly, giving rise to a demographic of only-child families that face distinct social risks. However, the evolution of these families over the past four decades remains insufficiently documented. Using data from national population censuses and one-percent sample surveys spanning 1982 to 2020, this study applies life tables and probabilistic methods to examine changes in the structural indicators of only-child families based on the sequence of familial mortality. It further explores the effects of parental age at first childbirth and the spousal age gap. The findings reveal several key trends. First, over the past four decades, the likelihood of child loss has declined steadily, and the ages of both the child and the parents at the time of the child’s death have been delayed. When parents predecease their child, the child’s age at the time of parental mortality typically exceeds 60 years, with the duration of solitary survival remaining stable. Second, age-specific probabilities reveal distinct life-course patterns. When both parents predecease the child, parental death becomes dominant at later stages, typically when the child is over 63. In contrast, among bereaved only-child families, transitions to one-person households tend to occur after the 60th year following childbirth. The highest ultimate cumulative probability is observed for the father–mother–child death sequence (51.63%), while among bereaved only-child families, the father–child–mother sequence is the most probable (6.50%), and the mother–child–father sequence is the least probable (2.56%). Third, a higher parental age at first childbirth reduces the likelihood of experiencing bereaved death sequences; however, it also leads to a younger age at the time of the child’s death and a relatively stable duration of solitary parental survival. Conversely, when both parents predecease the child, the ultimate cumulative probabilities rise, the child’s age at parental death decreases, and the duration of the child's solitary survival increases. Additionally, these indicators are also sensitive to variations in the spousal age gap. These findings highlight the need for differentiated support policies, carefully tailored to the evolving dynamics of only-child family structures.